Ignorance: (On the Wider Implications of Deficient Knowledge)

Chapter 8 Implications of Ignorance

140 Preliminaries The preceding deliberations have brought to light a considerable variety of types of fact that, on the basis of general principles, are bound to be unknown or even unknowable. The categories at issue here are first and foremost the following: • Certain facts regarding our own ignorance • Certain facts whose determination requires inaccessible data or impracticable measurements • Certain facts involving information hidden in a statistical fog • Certain facts deliberately kept secret by others • Certain facts about the past that have left no trace • Certain facts regarding the detail of future discoveries 8 Implications of Ignorance rescher ign text.indd 140 12/19/08 9:45:52 AM Implications of Ignorance 141 • Certain facts regarding future contingencies • Certain facts involving vagrant predicates • Certain facts involving superior intelligences The basic principle that renders various types of fact unknowable are ultimately of two sorts: (1) those inherent in the contingencies of the world’s ways, and (2) those inherent in logico-conceptual considerations . Display 8.1 elaborates this distinction in greater detail. Our ignorance is sometimes grounded in operations of nature that render certain fact-determinations impossible in the circumstances, and it is sometimes grounded in the insufficiency of our informationaccessing resources. But more interesting yet are those cases of necessary ignorance where knowledge becomes unrealizable on logicoconceptual grounds—self-reflexive unknowing, predictive vagrancy, and intellectual disparity. Display 8.1. Grounds of ignorance • Contingent ignorance Ontologically grounded: rooted in nature’s modus operandi • Interventions of chance (How will the coin toss eventuate?) • Machinations of chaos (How will the smoke drifts dissipate?) • Trace erasure (Just what were sand dunes or cloud formations of a year ago?) Epistemically grounded: rooted in the inadequacy of our information securing resources • Inaccessibility of required data (What did Caesar have for breakfast on that fatal Ides of March?) • Inadequacy of observational resources (Just how many grains of sand are there in the Sahara desert?) • Necessary ignorance • Regarding the detail of our own ignorance • Regarding matters involving vagrant predicates • Regarding the working of superior intelligences rescher ign text.indd 141 12/19/08 9:45:52 AM 142 Implications of Ignorance The Vagaries of Vagueness While the present deliberations are focused upon ignorance, they nevertheless provide no basis for a radical scepticism. For they do not take the pessimistic line of a cognitive negativism to the effect that knowledge about the world is unachievable. On the contrary, the present approach is one of cautious optimism, arguing that while reliable information is often not as readily achievable as people are inclined to think, the cognitive enterprise nevertheless can successfully come to terms with this fact. Evolutionary considerations afford us good reason to think that we exist in a user-friendly world where we need not be right about things for opinion-guided action to be successful. And indeed even in cognitive matters we can—strange to say—manage to extract truth from error. Let us see how this comes to be. One fundamental feature of inquiry is represented by the following observation: Thesis 1: Insofar as our thinking is vague, truth is accessible even in the face of ignorance. Consider the situation where you correctly accept P-or-Q. But—so let it be supposed—the truth of this disjunction roots entirely in that of P, while Q is of otherwise undetermined truth status. However, you accept P-or-Q only because you are convinced of the truth of Q, whereas P is something about which you have no information at all. Nevertheless, despite your ignorance, your belief is entirely true and appropriate.1 This example illustrates a far-reaching point. Thesis 2: There is in general an inverse relationship between the precision or definiteness of a judgment and its security: detail and reliability stand in a competing relationship. Increased confidence in the correctness of our estimates can always be purchased at the price of decreased accuracy. We estimate rescher ign text.indd 142 12/19/08 9:45:52 AM Implications of Ignorance 143 the height of the tree at around 25 feet. We are quite sure that the tree is 25±5 feet high. We are virtually certain that its height is 25±10 feet. But we can be completely and absolutely sure that its height is between 1 inch and 100 yards. Of this we can be “completely sure” in the sense that we are “absolutely certain,” “certain beyond the shadow of a doubt,” “as...