Space and Time

The border region between philosophy and physics is a fascinating area which has been inhabited and cultivated by a number of brilliant intellects over the centuries. One feature of the field is that nearly everyone who works in it arrives at the conclusion that one cannot adequately consider the nature of space without meditating on time, and conversely, one can’t really deal with time unless one also deals with space.

Going all the way back to Zeno of Elea, who lived around 450 B.C., and who arguably began modern physics and modern mathematics, we see the inseparability and interplay of space and time.

As Edmund Husserl wrote:

I am aware of a world, spread out in space endlessly, and in time becoming and become, without end. I am aware of it, that means, first of all, I discover it immediately, intuitively, I experience it. Through sight, touch, hearing, etc., in the different ways of sensory perception, corporeal things somehow spatially distributed ...

Ignoring Husserl’s comment that the world is “without end,” we see that space and time are unavoidable issues for philosophy, because they present themselves to us directly and in a manner which is prior to our formation of more complex concepts. Concepts about space and time are indeed themselves very complex, but our experience of them prior to the formation of complex concepts about any topic. Husserl also writes:

As it is with the world in its ordered being as a spatial present - the aspect I have so far been considering - so likewise is it with the world in respect to its ordered being in the succession of time. This world now present to me, and in every waking “now” obviously so, has its temporal horizon, infinite in both directions, its known and unknown, its intimately alive and its unalive past and future. Moving freely within the moment of experience which brings what is present into my intuitional grasp, I can follow up these connections of the reality which immediately surrounds me. I can shift my standpoint in space and time, look this way and that, turn temporally forwards and backwards; I can provide for myself constantly new and more or less clear and meaningful perceptions and representations, and images also more or less clear, in which I make intuitable to myself whatever can possibly exist really or supposedly in the steadfast order of space and time.

We orient our thinking and perceiving within the framework of time and space, and we understand objects, or our sensations of objects, within that framework. Again, Husserl asserts that time is “infinite in both directions,” but that is a separate topic: whether we agree with him on that or not, there are few, if any, conceptions which we can meaningfully form outside of time and space. What it means to be outside of time and space, and if anything is outside of time and space, is difficult to conceive, and disputed by various groups of philosophers. But the centrality of space and time, in both our perceiving and in our reasoning, is indisputable.

What is Knowing?

We know many things, or at least we think we do, and we use the word “know” everyday. But what is knowledge? What does it mean to know?

First, we must sort out the different uses of the word: I know my uncle, and I know that Abraham Lincoln was born in 1809. These are two very different mental states or processes. In philosophy, we are usually concerned with examples of the latter type - what we might call propositional knowledge: knowing that a proposition (a statement or sentence) is true.

One philosophical tradition suggests that knowledge is justified, true belief: it is justified, meaning that we have some reason to embrace it; it is true, because we would not say that one can know a falsehood ("I know that 2 + 2 = 5"); and it is a belief, because one can only know something if one also believes it.

A slightly different spin on knowledge is given by British philosopher A.J. Ayer, who writes

that the necessary and sufficient conditions for knowing that something is the case are first that what one is said to know be true, secondly that one be sure of it, and thirdly that one should have the right to be sure. This right may be earned in various ways; but even if one could give a complete description of them it would be a mistake to try to build it into the definition of knowledge.

Ayer is indicating that there would be different types of justifications for different types of facts: “I know that my neighbor’s car is blue” and “I know that my knee hurts” and “I know that 7 + 5 = 12” represent various types of knowledge. My answer to the question “how do you know?” will not only by different for each of the three, but will be of a different type.