1 Samuel 9:9 - "Formerly in Israel, when a man went to inquire of God, he said, ‘Come let us go to the seer’; for he who is now called a prophet was formerly called a seer."
It is presumed (especially when reading our text), that the office of the seer antedated the office of prophet in Israel, although the functions of each were the same. Our text is probably a gloss on the original text, added at a later date by someone who realized that Samuel was not a member of a roving band of ecstatics, such as the early prophets (see PROPHET), but that he was a solitary man in close communication with God, who spoke the messages of God.
The office of the prophet, as we generally think of it, did not clearly emerge until the tenth century B.C. at the earliest, but it is obvious that there were, at all times, men who were tuned in on God’s wave length, if we may say so, and who were commissioned to present God’s messages to the people. It is quite possible that the office of seer was lifted from the Canaanites, and then made into a distinctively Israelite profession through a process of refinement.
We do have specific instances of the non-Hebrew seer, who was actually a messenger of Yahweh, the God of the Hebrews. For example, in Numbers 22 to 24, we have the story of Balaam, a seer who was employed by the king of Moab at the time of the Israelites’ wanderings, but who actually became a spokesman for God.
However, there is one thing that we must remember - the earlier the time with which we are dealing, the more primitive the concepts, so it should be no surprise to us that the seers were often dabblers in fortune-telling and became involved with the baser forms of divination, such as wizardry, necromancy, and such practices which has been expressly forbidden. But there is a mysterious fascination about things, and the temptation was great. So we find that there were degenerate seers also in Israel.
I suppose that if we wish to make a more specific differentiation between seer and prophet, we might be justified in saying that the seer made his powers his profession and livelihood, and his functioning was habitually passive: he waited to be consulted. The great prophets, on the other hand, were men of all walks of life who were literally "plucked out of their ways of life" by God, and were driven to deliver God’s messages to his people.
Today I don’t suppose we have a profession or calling that parallels that of the seer, although we might not be too far off base if we compare him to the modern-day fortune-teller, who makes his living off the credibility of others, and who, in more cases than not, will predict what he knows the client wants to hear, rather than jeopardize that living.