Einstein MAY have been referring to the "persistent reality" of say, knowledge
Which as far as we should be concerned...is-never-ending*.
After all he was a celebrated Physics teacher of possibly the prime science
discipline (and possibly The Prime discipline of human knowledge).
He was,I believe, later asked-to-recant...(he refused).
We in philosophy (and therefore in prime objective Physics too) ought to understand just how believing-in-reality-as-an-illusion is detrimental to our free understanding of knowledge -- and in philosophy in particular it is responsible for the entering within of subjectivity and of Relativism et al.
As after a time of misconstruing or mistaking reality for illusion....students can become blind to the subjective/relative attack upon critical and rational facts.
Facts like we-can-learn-from-our-mistakes or that new facts must be critically
decided by us (as the larger group) to be BETTER THAN the old facts...
both of these such facts become MUCH LESS SO if we don't believe-the-world-is-real.
That is, if we refuse to understand that we-here-now do live in a reality (and NOT an illusion), a reality that is also commonplace because it constantly changes (notably for students and other learners, it changes as our knowledge changes..NOT BECAUSE our knowledge changes mind you).^^
And Einstein or Hawking or other scientists could further understand that our reality is now also one where criticism-as-a-tool for changing our reality for the better..has certainly taken a-hold ; that the persistent illusion of the history of either physics or of philosophy as not-being-critical enough, is changing for the better.
In physics as in other sciences we see this as a direct result of what bad changes humankind has been making to reality, non-illusionary changes which
fortunately the scientists still believe we can reverse for the better.**
In philosophy too there are great improvements being made in our western world ; gradually philosophers are being weaned-off of their recent "diet" of
(science) inductive-ism and onto/into a more encouraging and realistic world of "deductive-ism", where they not-only-belong but where better and better critically demanding knowledge is available to them. To us all in fact. By putting "inductive-ism" firmly into the rote, authoritative confines-of-history we
can then more easily see where and why we were mistaken in our reliance
upon such a method.We can state that it probably did little good for the philosophers among ourselves...although it has done great harm for science
and therefore the scientists among us.
And this is the real world that we live in, a 21st century of great -Great- hope and expectation from the past, together with those of us who remember that past too.^
Yet our students and philosophers here can rise-to-its challenge, for its been a
(futuristic) 21st century like no other(!) and no doubt it will continue along in such a vein ; and for knowledge seekers everywhere it represents an opportunity to do-ones-best in the search for more and more, better and better knowledge, of what we have going forward.
* free, open and-reality-enhancing, going forward
^^ Partly because of communication - the internet et al, which I have
written about before (contrasting it with a speculation or similar
reason why SOCRATES himself chose-to-teach ONLY by using
speech, not by using writing (of which he at least knew-of at that
** Fossil fuels and its UNFORSEEN danger to life.
^ a largely Non-critical past I/we should add..