Why ask why?
Answer by Helier Robinson
Asking why is requesting an explanation. Explanations are causal: to describe causes is to explain their effects. Even the most primitive human societies seek explanations; their explanations are what we call myths. Past systems of explanation were metaphysics and theology. Our everyday explanations are common sensical. Scientific explanation is theoretical science, which explains empirical science. In all these kinds of explanation imperceptible causes are invoked in order to explain perceptible events, and the description of the causes is speculative.
As David Hume pointed out, we cannot perceive causes, we can only perceive correlations; consequently he claimed that it is vain to speculate. But he was wrong. All of theoretical science is speculative, but it is speculation closely tied to empirical science and to reason (mathematics). If you ask a theoretical physicist what it is that theoretical physics describes, he/she will tell you that it describes the underlying causes of empirical phenomena, thereby explaining these phenomena. The word ‘underlying’ is metaphorical: the ground here is a bit shaky as far as common sense is concerned; but what is meant by ‘underlying’ is ‘imperceptible’. ‘Empirical’ means known through the senses, or perceptible, and ‘theoretical’ means non-empirical, or imperceptible. Nothing theoretical is ever empirical, although many people wrongly believe otherwise.
Consider a bacterium seen through a microscope: does the microscope enlarge the bacterium, or does it enlarge an optical image of the bacterium? It enlarges an image, of course. Bacteria are theoretical, imperceptible. Similarly with viruses, and electron microscopes, and with molecules and atoms, and scanning tunneling microscopes. The same is true of telescopes, including radio telescopes. Measurement is another misunderstood process. All measurements are empirical, but what they measure is usually theoretical. Consider measuring a temperature, for example: your thermometer reading is empirical but the thing measured is average kinetic energy of molecules, which is theoretical, imperceptible.