On his final page, Freud acknowledges that his theorising "in turn raises a host of other questions to which we can at present find no answer".[37] Whatever legitimate reservations there may be about "the improbability of our speculations. A queer instinct, indeed, directed to the destruction of its own organic home",[38] Freud's speculative essay has proven remarkably fruitful in stimulating further psychoanalytic research and theorising, both in himself and in his followers; and we may consider it as a prime example of Freud in his role "as a problem finder — one who raises new questions ... called attention to a whole range of human phenomena and processes".[39] Thus for example André Green has suggested that Freud "turned to the biology of micro-organisms ... because he was unable to find the answers to the questions raised by psychoanalytic practice": the fruitfulness of the questions — in the spirit of 'Maurice Blanchot's sentence, "La réponse est le malheur de la question" [The answer is the misfortune of the question]'[40] — remains nonetheless unimpaired.