Category Archives: history of philosophy

What the philosophers of the past thought and why.

Plotinus’ System

I just took notes on something about Plotinus. I’m going to summarize it here, because that helps me remember what I read. I do not believe any of this, I am just summarizing Plotinus for my own benefit. I’ll add my own comments at the end.


In Plotinus’ system, everything emanates necessarily from the Divine and strives to return there. The Divinity is a graded Triad consisting of three hypostases:

  1. The One,
  2. The Divine Mind, and
  3. The All-Soul.

I’ll go over each of these in turn.

The One is unknowable, because it transcends the knowable. It negates all quality, including qualities like goodness and existence. We can still refer to it as “the Good,” in the sense that it is the goal everything strives toward. We can also refer to it as “existing” if we keep in mind that this only means it does not have the quality of nonexistence.

The One is not Creator or the First Cause – the Creator falls lower in the Divine hierarchy. It has Supra-Existence, and acts in an eternal Super-Act. Nothing could exist without it. Language drives us to speak of it as a cause, meaning its perfection implies an act of producing something else. The most perfect thing is a mind, so it produces the Divine Mind.

The Divine Mind or Intellectual-Principle, unlike the One, is something that existence may be affirmed of. It is an Intelligence, and a mediation to us of the One. It is the beginning of plurality and complexity, and it contains the Divine Thoughts (these are Plato’s Forms – Plotinus is heavily influenced by Plato). The Divine Ideas are the archetypes of everything that exists in the lower spheres.

The Divine Mind contains all particular minds, which are “shadows” of the Divine Mind. It cannot be unproductive, because its Act of Thought comes with an Act of Act. Therefore, the Divine Thinking creates the All-Soul.

The All-Soul is an eternal emanation of the the Divine Mind. The Divine Mind has two Acts: it contemplates the One, and it generates that which is lower in the hierarchy. Likewise, the All-Soul has two Acts: It contemplates the Divine Mind, and it generates the lower realms upon the model of the Divine Ideas. We can verbally partition these two aspects or acts of the All-Soul by referring to them as the Leading Principle of the Soul and the Lower Soul, respectively.

The All-Soul is the Logos or ordering principle of the universe, the mobile cause of movement and form, and the Creator of everything lower. As its name suggests, it includes all souls.


This is very weird stuff. My understanding is that Plotinus claimed to know all of this through mystical experience, which explains the apparent arbitrariness of his worldview. Nevertheless, he does offer arguments for some aspects of it, and I may cover those arguments later.


Plato’s Dialectic

Plato held that in philosophy, we arrive at the truth by means of a process of “dialectic.” Dialectic, for Plato, works as follows:

  • We begin by having one person put forward an answer to the problem in question on the basis of certain arguments.
  • Another person then comes along, points out flaws in the first person’s answer, and puts forward his own answer.
  • Then a third person comes along, criticizes both viewpoints, and puts forward an answer that is better than either of them.
  • etc.

Plato held that, over time, this process leads us closer and closer to the truth. This is illustrated by some of his dialogues.

Plato’s theory assumes that we have a way of rationally evaluating an answer to a philosophical question as plausible or implausible. Plato held that we could see this “intuitively,” but his account of intuition depends on his metaphysics, which most philosophers have rejected.

Another perspective on dialectic comes from David Hume. Hume agrees that it often happens in philosophy that one person puts a position forward, and then another person criticizes it and puts their own position forward. However, according to Hume, the intuitions that this process depends on are subjective products of “habit or custom.” So, while dialectic can arrive at conclusions that better appeal to a given person subjectively, it is not a source of objective truth like Plato thought.

I think the only way to answer Hume once and for all is to present a body of demonstrably true conclusions in philosophy. So long as philosophy is seen as an endless debate, many will be inclined to question whether it has any cognitive status at all. There have been a number of attempts to do this since Hume, and evaluating all of them is beyond my scope here.

Where Plato Meets Hobbes

In many ways, Plato and Hobbes couldn’t be more different. Plato was an idealist, and Hobbes was a materialist. Plato advocated free will, and Hobbes was a determinist. And, famously, Plato believed in the Forms, whereas Hobbes was a staunch nominalist. But despite their differences elsewhere, the political philosophies of Plato and Hobbes are strikingly similar.

Plato advocated a dictatorship ruled by philosophers, on the grounds that philosophers alone have cognitive access to the Form of the Good. If a philosopher is given intensive training and education over the course of decades, he will be able to pierce the veil of perception and see what is really good. And once he has mystic insight into what is good, there is no reason why he shouldn’t use force to get any misguided citizens of the Republic who disagree to obey him.

Hobbes’ dictatorship was not ruled by mystics, like Plato’s. Instead, Hobbes, claiming to be an advocate of science, advocated a dictatorship run by arbitrary whim. Words like “good” and “justice” are controversial, and there is no objective way to settle disputes about these ideas, since they are subjective. So, according to Hobbes, everyone should submit to an all powerful Leviathan out of fear of anarchy, and just agree to treat the ruler as right by definition.

Why did Plato and Hobbes both end up advocating tyranny, even though they disagreed on so many points? The answer is that, although they might superficially look like opposites, mysticism and subjectivism can both lead to tyranny in practice. Mysticism can lead to a dictatorship ruled by mystics, whereas subjectivism can lead to a dictatorship ruled by the feelings of the dictator.

Reading Philosophy

I’ll explain how I approach a philosophical text, then list some books you can read to refine your approach further.

Reading Philosophy

The main thing when reading a philosophical text is to read actively – take notes, write in the margins, anything so that you’re not just letting the words pass over you. In addition, you need to read any philosophical text that you want to understand and remember a minimum of two times.

The first time you read a philosophical text, you need to put aside your personal views and just try to understand what the text is saying. Don’t evaluate the argument at this point, or your evaluation will distort your understanding of the content of the argument. Be able to prove that the philosopher is actually asserting each component of the argument you think he is making with specific passages in the text.

Once you understand the argument of the text, you can read it again to evaluate the argument. It helps many people to make an “argument map” or lay out the argument of the text in front of them as a syllogism so that the premises and inferences are clearly displayed.

If you read a philosophical text carefully, take notes, evaluate it thoughtfully, and write an essay explaining your point of view, there is a good chance you will remember it for the rest of your life.

Book Recommendations

One book that was recommended to me by a very good professor when I was a college freshman is The Practice of Philosophy by Jay F. Rosenberg. Rosenberg focuses on how philosophical worldviews get articulated and defended in the dialectical process of formulating and criticizing arguments, and he presents some common ways in which philosophical arguments are criticized.

Lewis Vaughn’s book Writing Philosophy is good, as well. It has two chapters that cover how to properly read a philosophical text, and it covers how to formulate and criticize a philosophical argument.

If you want a text that covers some basic issues along with readings, you might try Core Questions in Philosophy by Elliot Sober. Sober presents classic philosophical arguments clearly and explains how a philosopher could go about criticizing them. There is also a section near the beginning that explains inductive and deductive arguments.

Rationalism vs. Empiricism

The Stanford Encyclopedia of Philosophy has a great article explaining the basics of the rationalism – empiricism debate. It covers Descartes, Leibniz, Locke, Hume, and some contemporary thinkers. Kant is mentioned but not really discussed.

My position is closer to the empiricism side of things, if we go by the terminology of this article. I don’t think we gain any knowledge solely on the basis of deduction from a priori intuitions, although I think deduction plays an important role in knowledge, and I don’t think we have any innate knowledge or innate concepts.

Of course, there is a lot of work that needs to be done to establish this position, and I’m not going to attempt that here.


Was Kant an Atheist?

An interesting quote:

Scheffner was only too much aware of Kant’s belief that there was nothing to be expected after death. Though in his philosophy he had held out hope for eternal life and a future state, in his personal life he had been cold to such ideas. Scheffner had often heard Kant scoff at prayer and other religious practices. Organized religion filled him with ire. It was clear to anyone who knew Kant personally that he had no faith in a personal God. Having postulated God and immortality, he himself did not believe in either. His considered opinion was that such beliefs were just a matter of “individual needs.” Kant himself felt no such need.

(Source: Kant: A Biography, by Manfred Kuehn, p. 2-3)

There may be some controversy about this among Kant scholars.

Anthony Kenny on History of Philosophy

In this post, I will summarize Anthony Kenny’s description of his approach to history of philosophy, as given in the general introduction to his massive one volume history of philosophy, A New History of Western Philosophy.

Kenny first distinguishes his approach to history of philosophy from that of philosophers who view the history of philosophy as leading up to their own system, as, for example, Aristotle and Hegel did. Kenny says that he lacks the “supreme self-confidence as a philosopher” to approach history of philosophy like that, and for that matter, he thinks it is legitimate to question whether philosophy makes progress at all.

Kenny says that philosophy can be compared either to science or to art. If we compare it to science, we will see philosophy as producing an ever expanding body of scholarship that has surpassed the great philosophers of the past, like Plato. If we compare it to art, we will see a great work of philosophy as a product of individual genius that never gets outdated.

The view Kenny himself adopts, however, is in between these two views. Philosophy is not a matter of acquiring new knowledge but of organizing what we know, and this is so difficult that only a small number of geniuses can do it. The rest of us are forced to look up to them and take what we can from their ideas.

Kenny claims that philosophy is the discipline that the sciences emerge from, and that “a discipline remains philosophical as long as its concepts are unclarified and its methods are controversial.” He gives two examples. First, the issue of whether our ideas are innate or learned from experience was originally philosophical, but then was partly taken over by psychology, with certain issues pertaining to a priori knowledge remaining philosophical. Second, Aristotle believed that there was a branch of philosophy called “theology,” but “when we read what he says of it today, it seems to us a mix of astronomy and philosophy of religion.” Philosophy has no distinctive subject matter, only a set of methods.

At this point, Kenny considers the view that philosophy only has the therapeutic role of untangling confusions that people have gotten themselves into. To emphasize that this view is consistent with the existence of philosophical progress, Kenny gives the example of when Plato clarified Parmenides’ mistake over two senses of the verb “to be”:

Plato, in one of his dialogues, sorted out the issues so successfully that there has never again been an excuse for mixing them up: indeed, it now takes a great effort of philosophical imagination to work out exactly what led Parmenides into confusion in the first place.

Progress of this kind is often concealed by its very success: once a philosophical problem is resolved, no one regards it any more as a matter of philosophy.

Another example of philosophical progress that Kenny says is consistent with the therapeutic view of philosophy is making new distinctions; for example, philosophical discussions of free will are now required to take compatibilism into account, not merely phrase the issue as a dispute between libertarianism and hard determinism.

Another example of philosophical progress Kenny gives is reinterpreting classic works of philosophy, and he claims that one example of this is recent progress in scholarship on Aristotle and Plato. Here he makes a couple of points about history of philosophy. First, a historian of philosophy has to be a philosopher, because otherwise he would not be able to paraphrase past philosophers and fill in gaps in their reasoning as is required to do history of philosophy. Second, a historian of philosophy has to know about the historical context in which past philosophers wrote. He also points out that original philosophy requires engaging with the history of philosophy, as when Frege spent the first half of his book The Foundations of Arithmetic discussing rival theories.

Kenny next discusses exegesis. He distinguishes between internal exegesis, which attempts to provide a coherent and charitable interpretation of a philosophical text, and external exegesis, which attempts to relate one philosopher’s views to the views of other philosophers in order to bring out their significance. He also distinguishes between historical philosophy, which attempts to look for the justifications of the ideas in the text, and history of ideas, which looks for the motives that led a thinker to put forward the ideas that they did. He points out that a good original philosopher can be a poor exegete, as when Wittgenstein attempted to explain Augustine’s theory of language in the beginning of Philosophical Investigations.

Kenny points out that the skills of the historian can be more important than the skills of the philosopher or vice versa, depending on the purpose of the inquiry in question. The relative importance of these skill sets also varies depending on the area of philosophy in question. For example, ancient metaphysics will seem pointless to someone without a deep concern for the philosophical issues it addresses, and ancient political theory will probably be misinterpreted by a philosopher who projects democracy in its modern form back onto Plato or Aristotle.

Finally, Kenny concedes that he knows much less about the details of the philosophers he is discussing than a specialist on those philosophers would, but argues that it might still be valuable to provide a bird’s eye view of the history of philosophy.