What 4 artists are in Peter Paul Rubens' "The Four Philosophers"?

Answer 1

(The Artist himself) Self-portrait with Justus Lipsius, Philip Rubens, and Jan Wowerius, known as The Four Philosophers
c.1602
Oil on canvas
65 5/8 x 58 1/4 inches (167 x 148 cm)
Galleria Querini Stampalia, Venice, Italy