The first chapter of the book “Sic cogito” appeared in March 1891, published in The New Revue , with the title The Science of the Soul . In the next issues of the magazine there were published the other chapters: The Telegraphy of Love, Hypnotism in Spiritualism, The Materialism in Spiritualism, Excelsior.
Spiritualism attracted him also, as it had attracted Sir Oliver Lodge, who had lost his son, Victor Hugo, whose daughter, Léopoldine, had drowned in Seine together with her fiancé, and others. From a sentimental point of view, it could seem natural the attraction of man towards a world from „beyond”, where the defunct spirit, in the immense suffering of the survivor, could continue to manifest itself materially.
The spiritualism was founded by Léon Hippolyte Rivail, alias Allan Kardec, based on the „existence, occurrences and teachings of the spirits”. His books and the books of his collaborators, the subjects he magnetized, encircled in the process of vulgarizing a movement initially started with the purpose to counterbalance the invasion of materialism. Some of those who, as B.P. Hasdeu, had lost precious persons, accepted the ideas of Kardec’s works, enjoying the satisfaction of the possible existence of the „spirits” and willing to experiment this type of „communication”.
In the chapter God, Immortality, Confession, B.P. Hasdeu approached, first of all, the matter of religion regarded as an „embrace of three dogmas ”: God, immortality, confession, which can be found in any of its various forms. Free of any particularity, religion included them, theology, according to the scholar, thus being a science without ceasing to be faith, meaning that it „permits the cold and weighing cogitation, at the same time deeply moving the most sensitive chords of the heart ”. That was the explanation of the form in which B.P. Hasdeu regarded spiritualism, calling it „faith-science”. He defined God as the infinite with no borders, of which all the beings were created, the one which, having no boundary, includes everything in itself. The second dogma, immortality, was understood by the scholar, as all the spiritualists, in the philosophical-theological and occidental way, of preserving the human individuality. B.P. Hasdeu used the terms „delimitation” and „limitlessness”. The first one was the result of the action that implied creation, making, establishing limits. Out of infinite, the finite, the being, are delimited. The second notion represented the return to the Principle, to God – the creator.
What is the role played by sleep for the human being – this was the question raised by the scholar after the short introduction to the second chapter of Sic cogito. „To sleep means to dream ”, and he considered that the dream „is already an impulse to the unlimited ”.
The second chapter of Sic cogito shows that, in his attempt to demonstrate the independence of the soul towards space and time, as well as the possibility that the souls communicate with each other, B.P. Hasdeu appealed to two situations when the so-called „limitlessness” of the soul can be produced: dream and sleep-walking.
The starting point of B.P. Hasdeu in the next chapter, named The Telegraphy of Love, is the „infinite”. Using the two concepts, „delimitation” and „limitlessness”, the scholar defined three types of love, manifested as „altruism”: sexual (altruism and delimitation, which characterized the human body or the sub-organism), nonsexual (altruism and limitlessness, which characterized the soul or the supra-organism) and marriage (sexual and nonsexual love).
“Sic cogito” deals only with the nonsexual love, which he termed as „the holy love [through which] the telegraph between the souls can occur, first between earth and above, and afterwards between above and above”.
In the chapter Hypnotism in Spiritualism, B.P. Hasdeu, referring to the two notions of „delimitation” and „limitlessness”, suggested that the „unconscious”, would occur in three states: delimited within the body, when only the „unconsciousness” works (in the waking state), delimited in the living body, but, at the same time, unlimiting itself in order to occur (for instance, in telepathy), totally unbound from the dead body and transformed into „spirit”. He asserted that the „inspiration was the highest stage of the spiritualist communication ”, his work being created due to a „friend from another world”.
In the chapter Materialism in Spiritualism, the scholar stated that „In the phenomenon of the spiritualist photography, the sensitive plate doesn’t transcribe a real shape, but only an idea that is occurring in a medium’s brain in that moment ”.
In the last chapter, "Excelsior" the scholar talked about the way in which „ an architectonic jewel was built exclusively through a chain of spiritualist suggestions”. „I receive the suggestion” is the phrase often used throughout the story about the creation of the funerary monument. „The spirit that inspired me in building the temple has always been my daughter”.
In the Epilogue, he set the angular stone in the construction of his spiritualist theory, asserting that the title of the book, Sic cogito, was „spiritually suggested to him ”, not personally, but through another medium’s hand.
The publishing and dissemination of the book “Sic cogito” brought a lot of popularity to B.P. Hasdeu, especially, among those who, the same as him, had lost precious persons. The letters published in the inedited Correspondence can be a proof.
Even though they were announced in the preface of the third edition of the work “Sic cogito”, the other two books, Ita sensum and Virtus rediviva haven’t been published. Was it possible that the two physical Studies on the spirit, which were published in The New Revue , were part of Ita sensum, the second announced work? In a spiritualist session, B.P. Hasdeu received indications regarding Bernard Vermont, the one who had to translate it into German. Afterwards, there was no further reference to it; about Virtus rediviva no information has been discovered.
“Sic cogito” was the first Romanian book on spiritualism, in which, as noticed, B.P. Hasdeu presented personal experiences and testimonies, but also the results of some foreign personalities involved in the positive research, but also in the experimental verification of the paranormal phenomena.