Time changes, people change, circumstances change, things change. Is it a philosophical truth that everything changes?
'Time changes, people change , circumstances change, things change. Is it a philosophical truth that everything changes ?'
Doesn't the remark imply or presuppose some constants ? If time changes it must remain in order to change - otherwise it would not have changed but passed out of existence. If people change, don't they remain people - don't they remain as the subjects of change ? Else again they would cease to be people ? If my circumstances change the new circumstances remain my circumstances. 'Things' is too wide and general a term to discuss precisely but if a thing such as a chair changes by being painted white when it previously had been blue, doesn't the chair remain.
Also two side comments :
Some things cannot change, e.g. the number 7 though our knowledge of its properties might alter.
There are changes which some things cannot undergo because the alteration of their state causes them to cease to exist. If I die immediately after writing this mail, I have not changed; I have ceased to exist.
Is change the only thing constant?
The word "thing" has got different meanings. When it means an object, change is not a thing. It is also used to refer in an approximate way to an idea, subject, event, action, etc. Then the answer to this question is "No". As you mentioned in your question, time changes, people change, circumstances change, things change. But there must be/is a changeless thing behind all these changes. And Hindus call it Brahman. Some people call it God. This word (God) is being used in different meanings. So, that word is insufficient to 'illustrate' Brahman. It is beyond philosophical truth also.
I believe we have seen strong evidence that everything changes, especially from a scientific perspective. However, the true answer to whether everything changes or not is an open question. Indeed philosophers have pondered whether we could even become aware of something which is not changing, for the concept of awareness is tricky in that aspect. Many religions, such as the Abrahamic religions treat the presence of God as a constant, but proofs for religious topics are indeed hard to come by.
I think the phrasing "Everything changes" has been an effective philosophy because it contains a thinly veiled paradox. Generally speaking, I have found the popular paradoxes in philosophy tend to encourage further thought, especially thought that frees one from the confines of language. If I interpret such a phrase logically, it suggests that
change is a constant, and thus there is something that is constant, so not everything changes. The phrasing "The only constant is change" is a rewording that strives to escape that paradox, but runs into other linguistic challenges regarding whether "everything" is a "thing" which can be defined in such a way as to be constant or not. Many, such as Alan Watts, argue that once you have identified that which the noun "everything" represents, you find that it is no longer something that can be given a name. (If memory serves, he uses the Hindu term nirguna to capture the idea of something that cannot be given a name)
The expansion of the universe is accelerating, so we expect a 'heat death', an essential static state of hydrogen atoms and photons getting ever further apart, with no variations in the part. So by most reasonable definitions, unchanging. More generally, there is finite entropy so things wind down and decay into stable states, barring intervention.