I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.
Interpretation
Newton emphasizes the importance of empirical evidence in understanding gravity, rejecting unproven theories.
In this quote, Isaac Newton asserts that true knowledge must be derived from observable phenomena, specifically in the context of understanding gravity. He critiques the reliance on hypotheses that are not grounded in experimental evidence, highlighting a foundational principle of scientific inquiry that prioritizes empirical observation over speculative or metaphysical explanations. His stance reinforces the need for a rigorous methodological approach in the pursuit of scientific knowledge.
In practice
In a science class discussing the principles of gravity and experimental methods.
The best and safest way of philosophising seems to be, first to enquire diligently into the properties of things, and to establish those properties by experiences [experiments] and then to proceed slowly to hypotheses for the explanation of them. For hypotheses should be employed only in explaining the properties of things, but not assumed in determining them; unless so far as they may furnish experiments.
Plato is my friend, Aristotle is my friend, but my greatest friend is truth.
His epitaph: Who, by vigor of mind almost divine, the motions and figures of the planets, the paths of comets, and the tides of the seas first demonstrated.
And from true lordship it follows that the true God is living, intelligent, and powerful; from the other perfections, that he is supreme, or supremely perfect. He is eternal and infinite, omnipotent and omniscient; that is, he endures from eternity to eternity; and he is present from infinity to infinity; he rules all things, and he knows all things that happen or can happen.
My Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments: In order to which, I shall premise the following Definitions and Axioms.
It is the weight, not numbers of experiments that is to be regarded.
The function of muscle is to pull and not to push, except in the case of the genitals and the tongue.
Evolution ... is opportunistic, hence unpredictable.
The way to understand how different species evolved is to think about the niches that they fill in an ecosystem - basically, how they make a living.
It is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I'd rather not consider that).
Freedom is the oxygen without which science cannot breathe.
In the end, a theory is accepted not because it is confirmed by conventional empirical tests, but because researchers persuade one another that the theory is correct and relevant.
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