Natural theology and natural law › Degrees and natural ends

The fourth Way begins with degrees of goodness, truth, and nobility. Aquinas reasons from these comparisons toward a maximum and then toward a cause of being and perfection. The premises concern the relation between degrees, their maximum, and causal explanation; observing comparative language alone does not establish them.

For a hypothetical comparison, knowing that one runner is faster than another does not identify an existing fastest conceivable runner. The illustration shows why a general inference from ranking to an existing maximum would be inadequate. A defense of Aquinas must explain why the perfections he considers support a stronger connection, rather than treating any ranked quantity as sufficient.

The fifth Way concerns natural things without intelligence that regularly act toward ends. Aquinas compares their direction to an arrow directed by an archer and infers an intelligent director. An end here is what an activity is directed toward; it need not be a purpose consciously entertained by the thing acting.

The argument is therefore broader than an observation that one organ looks complicated. Its premise concerns regular directed activity in nature. A critic can ask why that regularity requires intelligence, while a defender must explain the proposed dependence. Neither repeating the archer comparison nor reporting a natural regularity settles that question on its own.

The Ways can thus be studied without declaring them either automatic successes or obsolete curiosities. Each contains an observation and a proposed explanatory principle. The point at which observation becomes explanation is where careful evaluation begins.