Macbeth is certainly an example of the conflict within all people as they strive to achieve acclaim in their personal capacity and become famous or infamous - as in the case of Macbeth himself- and to what expense.
Macbeth sacrifices his sanity due to his "vaulting ambition" and his choices indicate more than just foolishness in his decision-making. He is unduly influenced by his wife and the witches and his own over-zealous desires. He is no less responsible however for everything that happens to him.
There are many opportunities for Macbeth to come to his senses and he almost " proceed(s) no further in this business."(I.vii.31) having considered Duncan's "faculties so meek"(17). It is true that honor was highly sought in Shakespeare's day and Macbeth has proven himself in battle - hence the accolade from Duncan in making him Thane of Cawdor. However, Lady Macbeth knows how to manipulate Macbeth and throws aspersions on his manhood -"When you durst do it, then you were a man" (49) steeling him to proceed.
It is ironic that, if Macbeth wanted to prove his manhood, he would have stood up to his scheming wife, not capitulated! It is subsequently Macbeth's fear of being caught that overrides his decisions, not any desire to stop his murderous cause.
Macbeth and Banquo both hear the witches prophesy that they will accede to the throne - or their heirs will and yet, their responses are so different. Banquo is excited by the prospect but warily so as "the instruments of darkness tell us truths"(I.iii.124) and even Macbeth considers the prophesies as they "cannot be ill; cannot be good."(131)This does not stop him from removing Banquo and also trying to murder Banquo's son Fleance.
The fact that Macbeth returns to the witches - as if for encouragement does reflect his bewilderment and confusion after seeing Banquo's ghost but Macbeth is even angered by the witches as, althought they tell him what he wants to hear, he knows that there must be a deeper meaning as all men are "of woman born" and it is ridiculous to consider Birnam Wood advancing. By this stage Macbeth has lost all sense of rational thought and this is not just foolishness.
The witches themselves are aware that Macbeth is "a wayward son Spiteful and wrathful" (III.v.11-12). They manipulate but never intervene in any of the murders or evil deeds taking place in Macbeth.
As Lady Macbeth descends into a state of madness as "more needs she the divine than the physician" (V.i.72), Macbeth is unaware as he is so obsessed with advancing himself. Upon her death, Macbeth's acknowledgement that life "is a tale...signifying nothing" (V.v.27) is perhaps the beginning of his realization that the witches are nothing more than "juggling fiends." (V.viii.18) It is too late for him though and the only way to redeem himself is to fight to the end "Lay on."