 In the twentieth century, Hartley’s Observations remained outside the philosophical curriculum: philosophers-in-training could follow the well-traveled route from the “British empiricists” to Kant without turning aside to pick it up. And even if a person had wanted to, doing so was difficult, for after the editions of 1749, 1775, 1791, 1810, and 1834, and translations into French (1755 and 1802), German (1772), and Italian (1809), no further editions were published. Today, paperback reprints of earlier editions are available, but there is no modern critical edition.