Existence is relative, not absolute. I love philosophy and I am not an academic but a mere bartender, which has educated me empirically. You need to define existence beyond the lexicon to be given an exact answer unless you want a poetic answer. Everything is relative! The day I can undeniably experience something objectively true is a day I will look forward to, but the confusing truth is you can only see, hear or feel the world through your own perspective. Even the most pure or scientifically of hearts there is no absolutes.