Complex sentence: During the war his brother in law, Jaap van Domselaer, moves into the apartment to hide from the'Arbeitseinsatz' and he introduces Constant to Plato, Spinoza, Descartes, Kant, Hegel and Marx.
Split into simpler sentences: During the war Constant's brother in law, Jaap van Domselaer, moved into the apartment to hide from the' Arbeitseinsatz. ' He introduced Constant Plato, Spinoza, Descartes, Kant, Hegel and Marx.