"From principles is derived probability, but truth or certainty is obtained only from facts"

In this quote, Tom Stoppard is highlighting the distinction between likelihood and reality. He suggests that while probability can be stemmed from principles, it is only through facts that we can genuinely get certainty and reality. This indicates that principles, or general beliefs and ideas, can supply us with a sense of probability or possibility, however it is only through concrete evidence and facts that we can really understand and know something to be real. Stoppard's words remind us of the significance of looking for and depending on factual details in order to gain a much deeper understanding of the world around us.