A four-factor model of spiritual intelligence is first proposed. Supportive evidence is reviewed for the capacities of critical existential thinking, personal meaning production, transcendental awareness, and conscious state expansion. Based on this model, a 24-item self-report measure was developed and modified across two consecutive studies . The final version of the scale, the Spiritual Intelligence Self-Report Inventory , displayed excellent internal reliability and good fit to the proposed model. Correlational analyses with additional measures of meaning, metapersonal self-construal, mysticism, religiosity, and (...) social desirability offer support for construct and criterion-related validity. According to both intelligence criteria and current psychometric standards, findings validate the proposed model and measure of spiritual intelligence. Future directions are discussed. (shrink)

This is the first investigation of timekeeping by the sun and stars and the regulation of the astronomically-defined times of Muslim prayer. The study is based on over 500 medieval astronomical manuscripts first identified by the author. A second volume and third volume, also published by Brill, deals with astronomical instruments for timekeeping and other computing devices.

In this paper I examine a recent scientific claim that travel into the past, so long as a ‘consistent’ trajectory is followed, may be possible. I then argue that the possibility of such travel has unexpected implications for the free will‐determinism debate. In particular, human existence may be, at best, determinate but uncaused.

Only recently have the abundant sources relating to the application of astronomy to the needs of religious ritual in medieval Islam been studied, and it is now possible to write a new chapter in the history of Islamic astronomy. Simple techniques were advocated by the scholars of the religious law, highly sophisticated and complicated solutions were proposed by the Muslim scientists. It is not without interest to compare and contrast this activity, which lasted over a millennium, with that of the (...) monks of the Christian Middle Ages. The history of the latter has not yet been written, and cannot be written from textual sources alone, as is clearly shown by some of the astronomical instruments presented here. The present essay, in which both the Islamic and Christian traditions are discussed side by side for the first time, is very much a preliminary venture, primarily intended to point to the inherent interest of the available materials for the history of science as well as for several other disciplines. (shrink)

This is the first investigation of one of the main interests of astronomy in Islamic civilization, namely, timekeeping by the sun and stars and the regulation of the astronomically-defined times of Muslim prayer. The study is based on over 500 medieval astronomical manuscripts first identified by the author, now preserved in libraries all over the world and originally from the entire Islamic world from the Maghrib to Central Asia and the Yemen.

This is the first investigation of timekeeping by the sun and stars and the regulation of the astronomically-defined times of Muslim prayer. The study is based on over 500 medieval astronomical manuscripts first identified by the author. A second volume, also published by Brill, deals with astronomical instruments for timekeeping and other computing devices.

Julia Knopes (2025) claims that peer providers are drawing from two models of disability, the medical and neurodiversity models, to understand their experiences. I take no issue with Knopes’s claim...

The author describes how Muslims over the centuries have determined the sacred direction towards Mecca and presents two highly sophisticated Mecca-centred world-maps for finding the qibla . These recently-discovered world-maps have forced a reevaluation of Muslim achievements in mathematics and cartography.

Astrolabes serving all latitudes are very rare. This recently rediscovered sixteenth-century Spanish example raises a host of questions which can only be addressed by considering all other such instruments and the few available textual sources. The instruments can all be traced back, not always directly, to an invention of the eleventh-century Andalusian astronomer Ali ibn Khalaf, preserved in the Old Castillian Libros del Saber de Astronomía of King Alfonso X. The design of this particular astrolabe and the engraving on it (...) are investigated in detail, and the as yet unidentified maker is associated with the circle around Juan de Herrera, architect of the palace-monastery of San Lorenzo de El Escorial. (shrink)

Essays from the cutting edge of psychedelic research, from Breaking Convention 2017.