I am not too familiar with aikido and its techniques specifically since I have never practiced it but I do know the basics. I was wondering what aikido's philosophy is on "entering" or "attacking the attack". I guess it would depend on the type of aikido and I'm not exactly sure how many or what kind there are (I know of 2: O sensei and the more "harder" jujutsu like aikijutsu if I'm not mistaken).

I have studied jujutsu and was taught as a core principle to attack the attack, and when done correctly, it is extremely effective. I'm interested in aikidos principles of redirection and leading. Why not enter in as the attack comes in, rather than diverting or leading/moving out of the way, and THEN entering? Is it just the style or are there different points of views and reasons for this?

Any opinions and input appreciated. Thanks