Boundary Skirmishes in the Limits of Scientific Knowledge
It was with some pleasure that I noted studentsofphilosophy had reblogged my The Unity of the World According to Science (and a Scientific Ontology), which was itself a response (in part) to the same studentsofphilosophy reblogging my much earlier post, Of Distinctions, Weak and Strong. Re-reading my post on scientific ontology I now see that it was rather compact, that I crammed a lot into a small space, and that all of it could use further exposition. One of the nice things about a blog is that one can spend as much time as one likes on leisurely expositions, though how many readers will remain with for a “slow reading” (or, rather, a “slow exposition”) of an idea is another question.
In the aforementioned The Unity of the World According to Science (and a Scientific Ontology) I wrote:
“...at our current state of scientific knowledge the Big Bang represents a hard earliest bound to possible observation, and therefore a boundary to what can be connected to everything else in the scientific unification of the world.”
Treating the big bang as a hard earliest bound to possible observation leaves us with several possibilities concerning this boundary, which is both a boundary of cosmology and a boundary of scientific knowledge:
There is (or was) nothing before the big bang.
There was something before the big bang, but we can’t know what it is.
There was something before the big bang, and while we cannot yet know what this was, we may yet bring this present unknown withing the scope of observation, evidence, and thus scientific knowledge.
There was something before the big bang, but it can only be known through philosophical investigation, not through scientific investigation.
I am going to take these four possibilities one at a time.
1. There is (or was) nothing before the big bang
It has not been unusual for scientists to assert that it is simply wrong to state that nothing came before the big bang, because the big bang represents the origins of both space and time, so that it is nonsensical to speak of time before the big bang. It is not surprising that a scientific defense of creatio ex nihilo should, in the course of its exposition, invoke additional time-honored concepts of theology, such as the incomprehensibility of anything prior to the moment of creation.
But I want to hasten to point out that it is a perfectly respectable view that there was noting before the big bang -- but this is a philosophical or theological proposition, not a scientific proposition. When a scientist speaks of there being nothing before the big bang, he or she is speaking not as a scientist, but as a philosopher or a theologian, because there is no conceivable scientific confirmation or disconfirmation of nothingness. By definition, nothingness admits of no evidence, therefore admits of no observation, and therefore can never be a part of science.
We can affirm without hesitation that all we know, and everything we can now observe, can be traced back to the big bang and no further, and so the big bang is the origin of all cosmology and the limit of scientific knowledge, but whether or not it is the limit of all knowledge, tout court, is another question. I have encountered cosmologists who make more-or-less this assertion, and, when pressed, simply shrug their shoulders and evince no curiosity regarding anything as distant as the antecedents of the big bang. And, truly enough, there is world enough and time in our present universe to occupy us, make no doubt. But not everyone is satisfied by this, and we must ask the radical questions that lie beyond the scope of observation.
2. There was something before the big bang, but we can’t know what it is.
Acknowledging the boundaries of scientific knowledge is the first step in scientific wisdom, and acknowledging that the big bang represents a boundary of observation and therefore a boundary for scientific practice is the minimum necessary wisdom for the practice of cosmology. No one ever maintained that science is or must be total knowledge or it is nothing. If anyone has said this, they are wrong; it is perfectly fine for science to remain within the methodological limits that it has carefully constructed for itself. Only as such can science remain legitimate science. To ask science to go beyond its own self-imposed limitations is to ask it to cease to be science.
As I have noted in any posts, methodological naturalism must be kept distinct from ontological naturalism, and it is a violation of this distinction -- a metaphysical fallacy, if you will -- that attempts to draw an ontological conclusion from a methodological premise. Science limits itself to a particular methodology -- methodological naturalism -- and in so doing experiences great epistemic gains where other methods fail, but the cost of this disproportionate success is the abandonment of ontological claims. And certainly there are ontological claims associated with science, but these claims are not scientific claims; they are philosophical claims that provide the conceptual infrastructure of science.
While the position that we cannot know what came before the big bang is preferable to outright denial of an ontological possibility, such an assertion still remains firmly within theological grounds by its implicit invocation of the ineffable. Consigning all that we cannot now observe to the category of the ineffable has repeatedly appeared in the history of science, and it has been repeatedly falsified by the progress of scientific knowledge. What appears as an absolute boundary to observation and thus scientific knowledge crumbles upon new methods of observation that reveal new classes of evidence.
3. There was something before the big bang, and while we cannot yet know what this was, we may yet bring this present unknown within the scope of observation, evidence, and thus scientific knowledge.
Of the alternatives noted above, only this awareness that certain knowledge closed to us at present may be revealed to us in the fullness of time, is consonant with the history of the progress of scientific knowledge. Even this proposition, however, is strictly beyond the scope of science. The above is simply an expression of epistemic hope coupled with an inductive observation of past scientific progress, which Hume would tell us tells us nothing about the state of knowledge tomorrow. The whole of the scientific enterprise could come to a halt, and induction would reveal its distinct and distinctive limitations, and all science to date would still be as sound -- or as unsound -- as it has always been.
But at least this point of view acknowledges that some scientists at least are seeking more comprehensive theories that may someday admit of testing. Penrose in his conformal cyclic cosmology has sought to show that traces of earlier big bangs might be present in the current universe, providing an observational basis for events prior to the big bang. So, clearly, some scientists are thinking, or trying to think, beyond the big bang. Such tentative efforts are a necessary prelude to developing concepts that might someday be testable, even if they are not yet at that point of development.
4. There was something before the big bang, but it can only be known through philosophical investigation, not through scientific investigation.
While, as a philosopher, I am sympathetic to this point of view, it is radically non-constructive and implicitly invokes the impossibility of scientific knowledge of a certain kind, and this is a bridge too far. Certainly future scientific theories that breech the observational barrier of the big bang will be deeply indebted to philosophical investigations, regardless of whether this indebtedness is acknowledged, but the more restricted methods of science will eventually follow the more permissive methods of philosophy. Part of the restrictions of scientific methods follow from the innately constructivistic nature of science, which points to the radically non-constructive character of the above claim. The careful, painstaking methods of science will eventually follow where the intuitive leaps of intuition first reconnoitered terra incognita.
This claim could be revised a bit to make it both more palatable and likely also more accurate: there was something before the big bang, but while the big bang stands as an observational barrier today that only philosophical investigation can penetrate, some of these philosophical forays will eventually suggest evidence that can be observed by the higher technology methods of a later date, and at this point it will begin to become a scientific inquiry.
It is important to note that none of these four possibilities discussed above constitutes a scientific proposition: no evidence has been or can be advanced for their confirmation or disconfirmation. All four are either philosophical or theological propositions, albeit expressed in mostly scientific language. Perhaps it is the use of scientific language and scientific concepts that is problematic, in so far as so few scientists recognize the non-scientific character of invoking creatio ex nihilo or ineffability in popular expositions of cosmology.
If we take a traditional philosophical or theological concept and express it in terms peculiar to contemporary science -- terms that did not even exist in hoary antiquity when classic philosophical and theological concepts were first formulated -- it is apparently enough of a distraction that the ancient concept is mistaken for a contemporary concept.
A similar, though opposite, problem appears when scientists, seeking to communicate with the general public, invoke traditional theological concepts presumed to be more palatable than naked science.
Whether or not the expression of the traditional in modern terms, or the expression of the modern in traditional terms constitute metaphysical fallacies, like the inference noted above from methodological naturalism to ontological naturalism, the very least that can be said is that such contexts require care and caution if we are not to mislead.