Complex sentence: However, Newman maintains that in concrete life, the best we can achieve is converging probabilities in favor of a conclusion--we never get the concrete existential equivalent of logical certainty.
Split into simpler sentences: However, Newman maintained that in concrete life formal incontrovertible proof in favor of a decision is not possible--the best one can achieve is converging probabilities in favor of a conclusion. For Newman it is impossible to attain the concrete existential equivalent of logical certainty.