Argument from possibility

You recommend a course of action on the ground that it can now be done. The argument works by letting feasibility stand in for desirability: once the obstacle to doing something is gone, the fact that it is within reach is offered as reason enough to do it. It can be attacked by insisting that being able to do something is no reason to do it, or by disputing whether it is really feasible at all.

Example

We should send astronauts to Mars, because we now have the technology to get them there.

Standardised form

Sending astronauts to Mars (a) should be done (X) because sending astronauts to Mars (a) is now technically possible (Y).

Transformations applied: the sentence recast so that the course of action is the subject of both statements; “we have the technology to get them there” rendered as “is now technically possible”.

Classification

The subject is the same in both statements and the predicates differ, so the argument form is alpha (a is X because a is Y).

The conclusion “should be done” is a statement of policy (P) and the premise “is now technically possible” is a statement of fact (F), so the argument substance is PF.

The keyword FEASIBILITY describes the relationship between predicates Y and X. The argument lever can thus be formulated as “Being now technically possible (Y) is the FEASIBILITY of being done (X)”.

Not to be confused with

• Teleologic argument — The action is recommended as a means to a goal; here no goal is named, only the fact that the action is within reach. GOAL
• Pragmatic argument — The action is recommended for what it will bring about, not for being possible. CONSEQUENCE
• Argument from evaluation — The premise is a judgement of how worthwhile the action is, not a fact about whether it can be done. P ← V

Source

Invented example.

Notes

This is a proposed type that is not part of the current table of forty-two. It has a widely used negative counterpart — “we should not require it, because it cannot be enforced” — that runs on the same lever in the other direction, following the principle that ought implies can. The negative form is generally regarded as sound; the positive form, in which “can” is taken to yield “ought”, is the more contestable of the two and is therefore the more instructive to display.