In a certain series of lectures Emanuel Lasker asserts that in the French Defense e5 for white is "Inadviseable, as any advance of pawns unsupported by pieces always is." He cites the fact that the d-pawn remains immobile, which restricts the dark-square bishop from the a7-g1 diagonal and the a1-h8 diagonal and this cannot be changed without the aid of the opponent. 
Granted, this was said in what, 1895? But the common sense of it isn't any less true just because times were simpler then, before chess computers and such. So why do good players play advance variations, if they're so bad? What do we know now that Lasker didn't know then that makes it permissible to advance pawns unsupported by pieces in advance variations?

The simplest answer is that the advance gains a spacial advantage. Surely there are other factors depending on position, but that is one thing that they always do.

What Lasker speaks of as "common sense" sometimes seems (to me at any rate) a bit smug and simplistic.

In general I ignore general rules about chess thinking. Of course there are always exceptions.

And I take exception to these generalities, and find the whole thing a bit common.

Not to mention a bit surprising, considering his style!...lol

Oh well, I guess all they had back then was the Exchange. 

Hehe I share Steinitz's point of view on this matter. So space really is the ticket here, then? 

No, everybody back then used to play 3 ed.

 But we're talking about advance variations.

in the winawer variation e5 is pushed because white's knight is pinned

Maybe 100+ years after Lasker wrote Common Sense in Chess everyone else discovered a few details that he overlooked. 

The French was known as the King Pawn to King's Square Three Sneak.  Today most good players do not play 3.e5.  3.Nc3 is generally regarded as the best move to counter the French.   Nimzovich used to play the advance with the idea of sacrificing a pawn and using knights instead of pawns to hold the center, but effective counters to Nimzovich's  ideas are now known.

well, fischer once said that d-pawn openings were "dull and a draw."

many players like to play something off-beat against the french to avoid the ultra-sharp variations with 3. ... Bb4.  I banged my head against the french for years before I finally started playing the exchange variation to avoid all that, I content myself now to getting a slight advantage in the endgame rather than getting toasted in the middlegame.  playing the advance variation serves the same purpose, getting black into the kind of position he may not prefer, even if white gets little or no advantage out of the opening.

I play that sort of system and it has served me well, but I am afraid that as I play experts and masters in OTB more and more frequently that I will be putting myself at a disadvantage from the opening. Are there specific ideas that refute this idea?
@bigryoung: it certainly does make more sense in the winawer variation, it seems like a natural continuation :) 

After 1.e4 e6 2. d4 d5 3. e5 c5 then Nimzowitsch's idea was not to lose time on c3 but play 4.Nf3 with the idea of sacrificing a pawn and later capturing the pawn on d4 with  the knight as part of a piece center.   I don't know that the idea was refuted, but Botvinnik demonstrated how Black could get a comfortable game.  4...Nc6 5.Bd3 cd 6. O-O and Bc5 was Botvinnik's move developing a piece and defending the pawn.   White would eventually win back his pawn, but Black would get good counter-play on the c-file.

Yes, but when Steinitz made that remark...

King's Indian Attack doesn't destroy anything without trying, I'm afraid.