Yes, it was a very simple question. The answer is no. But here is a much more useful answer, to which all the other answers were alluding:
During a turn of Dominion, you are not allowed to do anything other than play Action cards during your Action Phase (spending an Action to do each, one at a time, precisely and completely following each card's instructions in order before doing anything else), play Treasures during your Buy phase (one at a time, precisely and completely following each card's instructions in order before doing anything else, and only before Buying cards), Buy cards during your Buy phase (spending a Buy and the appropriate number of Coins on each, one at a time, precisely and completely following any on-Buy instructions, and then precisely and completely following any on-Gain instructions), clean up during your Clean-Up Phase and then end your turn, advance to the next phase, or count your deck (only looking at the backs of the cards), unless a card specifically says you can do it. (Obvious non-gamestate-related things like talking and sipping on a beverage of your choice (being careful not to spill any and risk damaging the cards) are allowed, and non-obvious things like keeping track of the score with pen and paper are beyond the scope of this answer but should probably only be done with the permission of all other players.)
This answers the majority of rules questions. Teach a man to fish and all that.