difference between act and deed

I've been searching the internet, but have not quite found a satisfactory explanation between an act and a deed.

Both seem to have kind of a meaning of something done, though through my google and etymology searching the only apparent difference I can find is that "act" slightly hints at something more in the process of being done. (although not necessarily)

Surely there should be more of a difference between the two words. If they mean the same thing surely there would be no need anymore for two words and I also know act and deed can not always be interchanged in sentences, but what is the difference exactly then?

I'm left utterly confused, hope someone can help me and explain the difference...

Solution 1:

Surely there should be more of a difference between the two words. If they mean the same thing surely there would be no need anymore for two words

There are a lot of near synonyms in English, so this does not follow at all. It's particularly so when you consider that act entered the English language in the late Middle English period, from French, while deed was in the language from the very beginnings of Old English. Many, but not all, seeming redundancies in English vocabulary have a similar origin story.

It is true that there are differences in nuances. The primary one would be that an act would generally be need to be relatively remarkable before we would use the term deed. One can do a particularly brave or noble or dastardly or evil deed, but one can't really do a lazy or everyday or common deed. There's nothing technically wrong with the latter, but it wouldn't be an idiomatic use.

There are similarly some differences in what verbs and prepositions are used with either. One doesn't do an act, one cannot be in the deed of anything.

Solution 2:

Both words have other meanings as nouns, not related to one another. e.g.Act of Parliament, Deed of Conveyance.

Moreover 'act' can be used as a verb, whilst 'deed' cannot. (At least not in this sense. Legally I think you can 'deed' property to someone'.)

The ODE (not OED) suggests a 'deed' is something you do intentionally, whereas it is possible to commit an involuntary 'act'. And as Jon Hanna points out they attract different verbs and pronouns.