The Distinction Between How and Why Questions

As Marcelo Gleiser sees it:

We want to describe how Nature operates and for this there is nothing better than the scientific method.
However, it’s perfectly legitimate to ask whether this barrier between the how and the why is insurmountable. Could science one day explain the why of things? Sticking with physics, since things get murkier in other fields (can we one day understand why two specific people fall in love using cognitive neuroscience?), I’d venture to say no. Physics, by construction, cannot explain the why of phenomena, only the how.
In fact, you may even argue that why-like questions are not scientific. If “why” means purpose, then physics has very little to say about that. We can experimentally validate the laws of Nature, such as “energy is conserved,” but we don’t know why energy is conserved. If you say because we wouldn’t be here otherwise, you’d be saying nothing very useful from a scientific perspective. Science is complex enough just focusing with the how of things. For the why we have everything else.

Category: Observations


2 Responses

  1. V. V. Raman says:

    I agree with the thrust of this posting, but there a few things that need to be clarified: or else they could be read as false or misleading.
    1. If the assumption here is that the meaning of WHY is “For what purpose,” then of course this is true.
    But if you take a question like , “Why is the sky blue?”
    it can very well be answered by physics in terms of light scattering.
    Often, questions in science/physics are answered by developing theories. The question “Why is the hydrogen spectrum consist of certain wavelengths?” led to the formulation of the Bohr theory of the atom.
    The question “Why is there energy conservation?” is answered in terms of the time-invariance of physical laws.
    To repeat: Gleiser’s statement that science cannot answer why questions should be preceded by explaining the meaning of why as in the French (pourquoi) and German (warum) (Italian, Spanish likewise) sense of the word: For what purpose?
    However, if WHY means “On what basis?” “Due to what underlying reason?”, (as in, “Why is August 15 a holiday in India”?) then science can and does answer/tries to answer those questions.
    V. V. Raman
    Tension in Science and Religion
    May 6, 2010

  2. Peter says:

    When scientists poses a “why” question, the word becomes interchangeable with “how.” A scientific question about why something is, is a question of causation or measurement/description; it’s more of a defining question (unless they are making theoretical speculations, in which case they are approaching philosophy). When a philosopher asks a “why” question, however, they are probing existence itself – not to take it’s measure, but to discern and evaluate how best to think and act as humans.

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