On Scientifically Not Putting the Cart in Front of the Horse

Quite often in science we get a bit ahead of ourselves and begin theorizing wildly, which can very often be an excellent thought experiment in and of itself. But without some data to give proof to our theorems, we can be easily sidedtracked.  Never have I read a statement so poetically phrased to admonish against it as I have recently:

Werner R. Loewenstein (1926 – 2014), German born American biophysicist
in The Touchstone of Life: Molecular Information, Cell Communication and the Foundatons of Life (Oxford University Press, 1999)