some tremendous riddle which he
cannot explain--which he may have to wait years to get explained--
which as far as he can see will never be explained at all?

The poet says: "An undevout astronomer is mad," and he says truth.
It is only those who know a little of nature, who fancy that they
know much. I have heard a young man say, after hearing a few
popular chemical lectures, and seeing a few bottle and squirt
experiments: Oh, water--water is only oxygen and hydrogen!--as if
he knew all about it. While the true chemist would smile sadly
enough at the youth's hasty conceit, and say in his heart: "Well,
he is a lucky fellow. If he knows all about it, it is more than I
do. I don't know what oxygen IS, or hydrogen, either. I don't even
know whether there are any such things at all. I see certain
effects in my experiments which I must attribute to some cause, and
I call that cause oxygen, because I must call it something; and
other effects which I must attribute to another cause, and I call
that hydrogen. But as for oxygen, I don't know whether it really
exists. I think it very possible that it is only an effect of
something else--another form of a something, which seems to make
phosphorus, iodine, bromine, and certain other substances: and as
for hydrogen--I know as little about it. I don't know but what all
the metals, gold, silver, iron, tin, sodium, potassium, and so
forth, are not different forms of hydrogen, or of something else
which is the parent of hydrogen. In fact, I know but very little
about the matter; except this, that I do know very little; and that
the more I experiment, and the more I analyse, the more unexpected
puzzles and wonders I find, and the more I expect to find till my
dying day. True, I know a vast number of facts and laws, thank God;
and some very useful ones among them: but as to the ultimate and
first causes of those facts and laws, I know no more than the
shepherd-boy outside; and can say no more than he does, when he
reads in the Psalms at school: "I, and all around me, are fearfully
and wonderfully made; marvellous are Thy works, and that my soul
knoweth right well."

And so, my friends, though I have seemed to talk to you of great
matters this night; of the making and the destruction of world after
world: yet what does all I have said come to? I have not got one
step beyond what the old Psalmist learnt amid the earthquakes and
volcanoes of the pastures and the forest