đź“–Personal knowledge: towards a post-critical philosophy

Polanyi, Michael
  • p.xxvii Scientific detachment does not exist

    • This fact is less harmful for precise science (math, physics(?))

    • But it is destructive for biology, psychology, sociology


  • p.4 Direction to objectivity means away from our senses toward theory

    • theory is a screen between our senses and world

    • we will rely more on theories and treat our raw impressions as dubious

  • p.4 Theories are objective because

    • they are separate from us, can be expressed as a system of rules

    • that expression is independent from our fluctuations

    • can be accepted without regard to personal experience

      • (i.e., universal theory, less human-centric)

  • p.3 We don’t explore the Universe objectively. We pick what is around us and what is beneficial for humans. We explore Universe from the center in us and we use human language to describe it. We cannot eliminate human perspective from our picture of the world.

  • p.4 Of two forms of knowledge, we regards as more objective one that relies more on theory and less on personal experience.

    We would rely increasingly on theoretical guidance for the interpretation of our experience, and would correspondingly reduce the status of our raw impressions to that of dubious and possibly misleading appearances.

  • pp.4–5

    We abandon the cruder anthropocentrism of our senses—but only in favor of a more ambitious anthropocentrism of our reason.


  • p.9 Ernst Mach (Die Mechanik): scientific theory is merely a convenient summary of experience. Its purpose is to save time and trouble in recording observations.

    • a theory must not go beyond experience by affirming anything that cannot be tested my experience

      • if theory cannot be tested by observation, it must be revised to be so (“its predictions restricted to observable magnitudes”)

    • scientists must drop the theory immediately given an observation that contradicts it

  • p.9–10 According to Newton’s, there is a universal frame of reference.

    • Michelson & Morley experiments measured speed of light moving in different directions (relative to earth)

    • it was expected that measured speed of light will be slightly slower/faster in the direction of earth’s motion

    • the result did not confirm that

  • p.11 contrary to popular myth (of that time?), Einstein did not use Michelson&Morley experiments to develop relativity theory

    • Einstein’s theory of relativity was developed as a pure speculation

      • Einstein’s use of M&M experiment is a nice story to justify theory as rational and grounded in experience

  • p.11 Mach criticized Newton’s definition of space and absolute rest that it is untestable and called it meaningless

    • he claimed that the theory must be reformulated as to refer to relative motion of bodies only

      • this argument influenced Einstein

    • p.12 Mach was wrong. Newton’s idea is not meaningless but false (Einstein showed that)

      • (that’s quite a difference)

  • p.12 Moreover, Michelson&Morley experiment did not give results predicted by relativity: there was non-negligible difference in speed

    • the difference wasn’t reasonably explained by the time of writing (is it now?)

    • Miller reproduced this experiment thousands of times with even better equipment and observed this difference

    • p.13 Yet, Miller’s results were absolutely ignored and dismissed

      Nobody doubted relativity. There must therefore be some unknown source of error which had upset Miller’s work. —C. G. Darwin

  • p.14 Einstein and his followers committed themselves to the theory long before its verification by example.

  • p.15

    By [these examples], modern physics had demonstrated the power of the human mind to discover and exhibit a rationality which governs nature, before ever approaching the field of experience in which previously discovered mathematical harmonies were to be revealed as empirical facts.

  • pp.15–16 acceptance of a theory is influenced by its beauty or profundity. Humans prefer rational theories.

    • p.16 words “simplicity,” “symmetry” try to hide our preference for rationality

    • p.16 the ideal of knowledge is a set of statements that are “objective,” i.e., entirely determined by observation. there is no place for rationality (as rationality feeling is personal)

  • p.17

    the act of knowledge includes an appraisal; and this personal coefficient, which shapes all factual knowledge, bridges in doing so the disjunction between subjectivity and objectivity.


  • p.18 goal of the book: to show that complete objectivity is a delusion and is a false ideal

    • to offer “personal knowledge” as a substitute

    • p.18

      every system of thought has of course some loose ends tucked away out of sight

Unambiguous statements:

  • p.19 Readings of our instruments are facts but they are interpreted by humans (to mean latitude/longitude/etc)

  • p.19

    Even the most strictly mechanized procedure leaves something to personal skill in the exercise of which an individual bias may enter.

  • p.19 a case of astronomer Nicholas Maskelyne dismissing his assistant Kinnerbrook for recording passage of stars 0.5 seconds later than he himself would.

    • 20 years later, the measurement procedure was shown to be flawed: two equally skilled observers could record different result

  • p.20 personal judgment is executed when verifying a theory

    • “Contrary to current opinion, it is not the case that a proven discrepancy between theoretical predictions and observed data suffices in itself to invalidate a theory.”

    • there is personal judgment to call a discrepancy as “anomaly”

    • e.g., for 60 years, before the discovery of Neptune, the observation that could not be explained by mutual interactions of the planets, were (rightfully) set aside as anomalies in hope that something will be discovered that could explain that without impairing Newtonian gravitation