I Just Know! Aristotle and Sense-perception

by PDS

Aristotle, you will recall in yesterday’s post, has shown us one way of knowing something: through a demonstration or argument. This seems like a relatively straight forward way of knowing. However, Aristotle’s second way of knowing (which actually forms the foundations for demonstrations) is a little tricky to grasp, and probably far more controversial. In fact, in a few weeks time we shall explore Descartes’ attack on the broad idea of “Pre-existing knowledge”, which will probably make this idea of Aristotle’s easier to understand too. Let’s start with a phrase Aristotle writes near the beginning of his Posterior Analytics: “All teaching and all intellectual learning arises from pre-existing knowledge”

At first glance Aristotle appears to be following Plato’s lead by suggesting that all knowledge is pre-existing (see my earlier posts on the Meno). However, this is not an affirmation of innate knowledge; Aristotle certainly doesn’t mean that. What he means by pre-existent knowledge is knowledge which is “primary and immediate”; or, in other words, knowledge gained by an innate power or capacity. It is this capacity that gives us knowledge, for example, that “All men are moral”.

Why doesn’t Aristotle think that we have innate knowledge of true premises? He writes “it would be strange if we possessed [these starting-points] all along, since then we would possess knowledge superior to demonstration without being aware of it.” Nevertheless, Aristotle is aware of Meno’s paradox and the problem of coming to know something without pre-existing knowledge of it: “it is clearly impossible…..for us to acquire [these starting-points] if we are ignorant and have no predisposition for knowledge”.

His solution is “an innate power of discernment – what we call sense-perception”. For Aristotle, when we perceive particulars, such as a man called Bob, and then a man called Derek and then many other particular men, our memories retain these perceptions and forms what Aristotle calls “experience”. From this experience we now have a “universal” in our minds: the universal of man to be precise.

Let me put it another way: If we perceive a man called Bob, a “primitive universal” of man is in our minds, and if we continue to perceive particular men the universal of man is more and more firmly established in our minds. And this provides some of the knowledge that the premise “All men are mortal” is true. The objects of knowledge, then – the universals – are perceived by naturally noticing and remembering similarities between the particulars. The same would apply to the universal of women, the universal of potato…etc…

Finally, Aristotle says that this innate capacity to acquire pre-existing knowledge is more accurate and more sure than the scientific knowledge that proceeds from it. Aristotle says “there cannot be scientific knowledge of the starting-points…it is intuition that grasps the starting-points”. Or to point it another way: sense-perception, memory and the ability to gain knowledge of the universals cannot be demonstrated; these capacities are assumed to be true from the start.

We still don’t know much about this “intuition” and how it functions, but Aristotle’s’ key point is this: some knowledge you can’t prove with any argument or “demonstration”, but this knowledge is still more sure than the arguments which build on it.

In my next post – and leaping ahead hundreds of years in the history of ideas – I will explain how Descartes attempts to doubt these starting-points. Furthermore, he will try to demonstrate that they are true!

Does Aristotle’s idea of innate capacities solve Meno’s Paradox? What do you think about the idea of sure knowledge which doesn’t require an argument to believe?