Agreeing past participle with "on":

Question

Answer

Bonjour Umi !

Did you have a question regarding this lesson ?

Answer

Bonjour Aurélie, 
I am sorry for not completing my question. Somehow I lost the page where I was writing my question regarding the usage of "ON."
So my question is: "As Men, we always went off to explore new horizons" in the example for "on", why is it treated as a singular as indicated on the page for the lesson? "En tant qu'Hommes, on est toujours allé à la découverte de nouveaux horizons." Since "Men" is a plural, I thought that we needed to change the past participle accordingly. 
I would like to get an explanation to clarify my confusion, please.

Merci beaucoup,

umi

Answer

Bonjour Umi !

The distinction is whether "on" refers to "we" - i.e. the speaker and other people he's with - or to a broader, more abstract group - i.e. "people in general".

Here we used the generic "Men" referring to Humanity in general, hence the capital letter, so it belongs to the second case.

I hope that's helpful!
À bientôt !.