從這個角度來看，科學知識是沒有止境的。
The game of science is, in principle, without end.
He who decides one day that scientific statements
do not call for any further test,
and that they can be regarded as finally verified,
retires from the game.
( Karl R. Popper )
換句話說，比較起人類其他的知識，
科學家了解甚麼是「相對地可靠」的知識，
而且科學家知道科學知識的可靠程度會越來越高。
Science begins with uncertainty
and is founded on uncertainty.
It provides no final answer
to the riddle of the universe
and it has no absolute truths.
However, relative truths in science
are still far better than
our common beliefs or opinions.
When ordinary people’s unrestable beliefs
are challenged by critiques,
they often try to escape to a land
where facts do not matter so that
their beliefs become less “falsifiable”.
We know very little, and yet
it is astonishing that we know so much,
and still more astonishing that
so little knowledge can give us so much power.
( Bertrand Russell )
科學家明白自己知道些甚麼，到達甚麼程度，
亦明白自己其實很無知，
因為當一個舊的問題解了之後，
一連串更多，更困難的問題往往隨後產生。
似乎我們不知道的東西，
增長得比我們知道的東西更快。
所以 Karl R. Popper 指出：「科學始於問題，也終於問題。」
越來越高層次的無知，永遠揮之不去。
對科學家來說，這既是一種無奈，也是一種刺激：
There is nothing which a scientific mind
would more regret than reaching a condition
in which there were no more problems.
that state would be the death of science,
not its perfected life.
( John Dewey, The Quest for Certainty, 1929 )
I personally dread the day when
there will be no more wonder in the universe,
no new problems to be addressed.
What a dull universe it will be for
that generation which solves the last problem.
Happily, I believe there is enough complexity in
the world to amuse human beings for all time.
( Isaac Asimov )
英國理論物理學家霍金 Stephen Hawking 亦指出：
「宇宙知識的探究將永無止境，我對這點是感到高興的。
找到終極理論再進行的科學探索，
猶如登上珠穆朗瑪峰後繼續尋找另一高峰。
人類需要這樣不斷探求知識。
我相信上帝一定十分沉悶，因為祂再無事物可以探索。」
最後，我們必須明白科學家當然沒法擺脫價值的判斷。
All sciences are now under the obligation
to prepare the ground for the future task
of the philosopher,
which is to solve the problem of value,
to determine the true hierarchy of values.
( Friedrich Nietzsche )