An improved version of The Principle of Naturalistic Closure

Here is James Ladyman and Don Ross' Principle of Naturalistic Closure presented in their book Every Thing Must Go (2007):

"Any new metaphysical claim that is to be taken seriously at time t should be motivated by, and only by, the service it would perform, if true, in showing how two or more specific scientific hypotheses, at least one of which is drawn from fundamental physics, jointly explain more than the sum of what is explained by the two hypotheses taken separately, where this is interpreted by reference to the following terminological stipulations: 

Stipulation: A ‘scientific hypothesis’ is understood as an hypothesis that is taken seriously by institutionally bona fide science at t. 

Stipulation: A ‘specific scientific hypothesis’ is one that has been directly investigated and confirmed by institutionally bona fide scientific activity prior to t or is one that might be investigated at or after t, in the absence of constraints resulting from engineering, physiological, or economic restrictions or their combination, as the primary object of attempted verification, falsification, or quantitative refinement, where this activity is part of an objective research project fundable by a bona fide scientific research funding body." (I omitted one stipulation)

The principle is supposed to rule out non-naturalistic metaphysics so I applaud the intention. However, it still leaves too much room for unscientific speculation, as long as the speculation takes science as its starting point. The parts of Every Thing Must Go where they present their positive metaphysical claims still resemble typical analytic philosophy. The style of reasoning and presentation is not very scientific. There isn't any detailed empirical evidence or complex mathematics. If Ladyman and Ross really are following their own principle in their book, then the principle is not constraining enough. Therefore, I now present to you an improved version of the principle:

Any new metaphysical claim that is to be taken seriously at time t should be a specific scientific hypothesis that might be directly investigated and confirmed by institutionally bona fide scientific activity at or after t as the primary object of attempted verification, falsification, or quantitative refinement, where this activity is part of an objective research project fundable by a bona fide scientific research funding body.

Notice the difference? Now the metaphysical theorizing must itself take place in a science journal instead of a philosophy journal. This should automatically rule out excessive speculation and philosophizing.


Does this leave any room for unification? Yes, because unification is already part of ordinary scientific inquiry (for example when scientists use both ecology and population genetics simultaneously to explain some facts), and the unifying hypotheses, or at least the properly scientific ones, will themselves make it through the institutional filters of science.