138

Logic 138

a fact of which the facts of a Premiss constitutes an Icon.
For example at a certain stage of Keppler's external exemplar of scientific reasoning he found that the observed longitude of Mars which he had long tried in vain to get fitted with an orbit were (within the possible limits of error of the observations) such as they would be if Mars moved in a ellipse.
The facts were thus in so far a likeness of those of motion in an elliptic orbit.
Keppler did not conclude from this that the orbit really was an ellipse; but it did incline him to that idea so much as to decide him to undertake to ascertain whether virtual predictions about the latitudes and parallaxea based on this hypothesis would be verified or not.
This was an Abduction.
(An Abduction is Origilary in respect to being the only kind of argument which start a new idea)
A Transuasive Argument or Induction is an Argument which sets out from a hypothesis resulting from