Good science - 1908 early geneticist

I am really enjoying hearing about the history of science in my EdX class I am taking.
My grades and performance isn't too impressive, but I am taking the class for fun, not credit. Although if I pass I will value the certificate they offer.

But today's lecture on early genetics had a passage that really impressed me, and I love hearing scientists speak about good science.

I'm not sure this is approved for me to post (off a YouTube video lecture), but I am going to anyway, and hope I don't receive consequences.

PROFESSOR: Section 2.
Fruit Flies and the Linkage.
To explain what resolves this, I have to tell you about one more person.
There's another really interesting person, a guy called Thomas Hunt
Morgan, who spends decades as a naturalist and an embryologist.
And he studies all sorts of different kinds of critters.
And he's fascinated by everything in the natural world.
And he has one of these labs where he kind of works on everything.
All sorts of crazy things are going on.
And when this whole Mendelism stuff comes back, he's interested in the
Mendelism stuff too.
But he is really an experimentalist.
He doesn't go in for this high-faluting theory.
Morgan is not a theory guy.
He's a data guy.
He's very suspicious of all this talk of factors and things like that.
In fact, Morgan begins to do genetics work in his lab, not to study
Mendelism, but to study evolution.
He starts crossing fruit flies together.
He starts about 1908, crossing fruit flies together in the hope that he's
going to discover evolution happening in the lab, new forms coming up.
We know it's going to be new mutants.
But that's not what he was looking for originally.
He's looking for these kinds of new forms.
And I know that in 1908, when he was beginning to do this work, he was no
believer in this whole chromosome business.
I actually found an article he wrote in 1909 that tells you what kind of a
skeptic he was.
He says "In the modern tradition of Mendelism, facts are being transformed
into factors at a rapid rate.
If one factor will not explain the facts, then two factors are invoked.
If two factors prove insufficient, now three will sometimes work.
The superior juggling sometimes necessary to account for the result
may blind us, if taken too naively, to the commonplace that the results are
so excellently explained, because the explanation was invented to explain
them." Just like what we talked about.
That was exactly what was bothering him.
"We work backward from the facts to the factors and then presto, explain
the facts by the very factors that we invented to explain them." That is a
good skeptical scientist.
He says I love your high-faluting theory over there, but
I'm not buying it.
And he's off making fruit flies.

Here a great link provided by the class. This is an excerpt of a Nobel speech in 1907 by Eduard Buchner.