These days, a passage from a book I read a while ago reoccurred to me several times. It sounds interesting and it seems to have a broad applicability in science (and in life, if you wish).
[...]
Look at the unknown. This is old advice; the corresponding
Latin saying is: "respice finem." That is, look at the end.
Remember your aim. Do not forget your goal. Think of what is
required. Keep in mind what you are working for. Look at the
unknown. Look at the conclusion. The last two versions of
"respice finem" are specially adapted to mathematical problems,
to "problems to find" and to "problem to prove" respectively.
[...]
From: G. Polya. "How to Solve It: A New Aspect of Mathematical Method", page 123, 2nd Edition, 1973.
The only addendum, perhaps, is that the goal may change time to time.
