The forceful fire of Aries together with the intellectual heat of Sagittarius is always a potentially interesting and stimulating relationship. This is one of those interactions that may work equally well in platonic circumstances as in traditionally romantic/sexual interactions. As the somewhat egocentric energy of Aries meets Sagittarius it is expanded and spreads itself widely; for as Aries symbolizes the finding of personal identity and the maintaining of that independent inner flame of being, Sagittarius is a highly interpersonal, social sign, striving to unite the spheres of culture and peoples on a higher plane.
Yet Sagittarius retains the frank naivety and enthusiasm of the fire signs, and the differences of these two signs are almost always productive and very rewarding for both. Energy combined with wisdom and confidence with faith is shown by this comradeship. It may be that Aries doesn't share the jupitarian religious or intellectual-spiritual "preaching" vein of Sagittarius, and Sagittarius thinks Aries too focused on a certain selected sphere of experience to connect to their broader vision, but in general they find each other and find each other well. The zest and curious quality of the relationship can be seen on a physical level as well as on a mental; they experiment, explore and expand together. An optimistic and romantic match.