Edwin Hubble(1887-1953) on the Method of Astronomy

Summary taken from M. Crowe's out of print book: "Modern Theories of the Universe from Herschel to Hubble", Dover Pub. 1994
from chapter 1.
It is worthwhile examining the claims that E. Hubble made concerning the methodology of Astronomy. As the most prominent astronomer of the 20th century his point of view must be seriously considered.

1) "Science is the one human activity that is truly progressive."
Hubble quotes from George Sarton:
'The saints of today are not necessarily more saintly than those of a thousand years ago; our artists are not necessarily greater than those of early Greece; they are likely to be inferior; and, of course, our men of science are not necessarily more intelligent than those of old; yet one thing is certain, their knowledge is at once more extensive and more accurate. The acquisition and systemization of positive knowledge is the only human activity that is truly cumulative and progressive."

There is a reason why claim 1) is valid.

2) "Science deals only with judgments concerning which it is possible to obtain universal agreement."
Quote from an article written by Hubble:
'Now, it is a curious fact that we are most certain about judgments that cannot be demonstrated. Subjective certainty is inversely proportional to objective certainty. Russell put the situation rather bluntly, "Who ever heard a theologian preface his creed or a politician conclude his speech with an estimate of the probable error of his opinion." .'

3) Universal agreement "is secured by means of observations and experiments" because these "tests represent external authorities which all men must acknowledge, by their actions, if not by their words, in order to survive."
Because of this science "is barred from the world of values." It can in some ways influence values but the reverse should not take place.

4) Observation and theory are two separate realms.
The observer collects sufficient data along with their estimated uncertainties and tries to find a common law that ties the data together. At this point the theoretician enters to establish theories based on these laws.

5) Good data and observations  are permanent contributions to knowledge but theory is ephemeral.
Observations and the laws deduced from them are permanent contributions to the body of knowledge, even given the fact that subsequently more precise observations may sharpen the predicitive power of the laws. However, theory changes as more data are obtained. Theoretical speculations have many forms and are eventually forgotten.

6) Precision scientific instruments are crucial for building astronomical knowledge. Telescopes were and are pivotal tools in exploring the cosmos.

7) Precise terms must be employed in astronomy
"The terms always carry the same same significance and substitutes are not employed. Variety is sacrificed for precision."