Quotes from Antoine Laurent Lavoisier

If, by the term elements, we mean to express the simple and indivisible molecules that compose bodies, it is probable that we know nothing about them; but if, on the contrary, we express by the term elements or principles of bodies the idea of the last point reached by analysis, all substances that we have not yet been able to decompose by any means are elements to us.

The art of drawing conclusions from experiments and observations consists in evaluating probabilities and in estimating whether they are sufficiently great or numerous enough to constitute proofs. This kind of calculation is more complicated and more difficult than it is commonly thought to be. . .