pleonasm

[mcgrant]

What is the difference between pleonasms and tautologies, and are they considered bad practice, to be avoided at all cost? Or not? And how about oxymorons?

Thanks

[CHOMAT]

Tautology is the expression of an idea by means of 2 different words. This is generally regarded as bad pratice. As far as pleonasms are concerned, the point is slightly different : we enter the realm of rhetorics and stylistics. Pleonasms have been used by great poets and writers just as oxymorons.
O brawling love, o loving hate,
O anything of nothing first create.
The co-presence of two seemingly contrary "signifiers" is close to a mere contradiction and yet it gives off a mighty effect.
You should be cautious with those stylistic means and avoid them within your academic or school writings .