The first thing these two signs feel for each other is respect. Both parts recognize the basic traits they share and see the other persons pride, passion and integrity as something they value in themselves. Hence, since the Aries is not normally the humblest or most self-loathing sign, there can be a spark of attraction and excitement. The typical Aries character tends to respond quickly and intensely, and if there is a potential flame in the interaction to begin with, it usually manifests pretty swiftly. The ultimatum for these two come after the dust has settled. What is left? Was the attraction based only on identification and satisfaction concerning the style and (re)presentation of the other, or can they offer each other something of lasting value?
There is a certain Aries type that is more retiring and seemingly shy or guarded, and it is possible for a lasting attraction to form between this type and the more traditional aggressive Aries type. They may find their outer differences to be in this case a good complement to the shared inner convictions and principles. But we have to understand that whenever these two come together, it's two of the most stubborn and self-righteous inviduals sharing space, and it's perhaps bound to fail if both persist in trying to take the lead or be the wiseguy.