The Principles of Physics

CHAPTER 1

WHEN the objects of an inquiry, in any department, have principles, conditions, or elements, it is through acquaintance with these that knowledge, that is to say scientific knowledge, is attained.

We do not know a thing until we:

• are acquainted with its primary conditions or first principles, and
• have carried our analysis of its simplest elements.

Therefore in the science of Nature, as in other branches of study, our first task is to determine its principles.

We start from the things which are more knowable and obvious then proceed towards those which are clearer and more knowable by nature.

The same things are not ‘knowable relatively to us’ and ‘knowable’ without qualification.

So we must advance:

• from what is more obscure by nature, but clearer to us
• towards what is more clear and more knowable by nature.

What is to us plain and obvious at first is rather confused masses. The elements and principles of these become known to us later by analysis.

We must advance from generalities to particulars.

It is a whole that is best known to sense-perception.

• A generality is a kind of whole, comprehending many things within it, like parts.

Much the same thing happens in the relation of the name to the formula.

For example, a name, ‘round’, means vaguely a sort of whole.

• Its definition analyses this into its particular senses.

Similarly, a child begins by calling:

• all men ‘father’
• all women ‘mother’

But later on distinguishes each of them.

CHAPTER 2

These principles must be either (a) one or (b) more than one.

If (a) one, it must be either:

• (i) motionless, as Parmenides and Melissus assert, or
• (ii) in motion, as the physicists hold
  • Some declare air to be the first principle
  • Others declare water.

If (b) more than one, then either (i) a finite or (ii) an infinite plurality.

If (i) finite (but more than one), then either two or three or four or some other number.

If (ii) infinite, then either as Democritus believed one in kind, but differing in shape or form; or different in kind and even contrary.

Some inquire into the number of existents – whether the ultimate constituents of existing things are one or many.

If many, whether a finite or an infinite plurality.

So they too are inquiring whether the principle or element is one or many.

Investigating whether Being is one and motionless is not part of the science of Nature.

The geometer has nothing to say to one who denies the principles of geometry.