idea has been taken on by later practitioners of Thelema, chaos magic and magick in general. They may consider that they are testing hypotheses with each magical experiment. The difficulty lies in the broadness of their definition of success, in which they may see as evidence of success things which a non-magician would not define as such, leading to confirmation bias. Crowley believed he could demonstrate, by his own example, the effectiveness of magick in producing certain subjective experiences that do not ordinarily result from taking hashish, enjoying oneself in Paris, or walking through the Sahara desert. It is not strictly necessary to practice ritual techniques to be a Thelemite, as due to the focus of Thelemic magick on the True Will, Crowley stated "every intentional act is a magickal act." Gnostic Mass Holidays The Book of the Law gives several holy days to be observed by Thelemites. There are no established or dogmatic ways to celebrate these days, so as a result Thelemites will often take to their own devices or celebrate in groups, especially within Ordo Templi Orientis. These holy days are usually observed on the following dates: March 20. The Feast of the Supreme Ritual, which celebrates the Invocation of Horus, the ritual performed by Crowley on this date in 1904 that inaugurated the New Aeon. March 20/March 21. The Equinox of the Gods, which is commonly referred to as the Thelemic New Year (although some celebrate the New Year on April 8). Although the equinox and the Invocation of Horus often fall on the same day, they are often treated as two different events. This date is the Autumnal equinox in the Southern Hemisphere. April 8 through April 10. The Feast of the Three Days of the Writing of the Book of the Law. These three days are commemorative of the three days in the year 1904 during which Aleister Crowley wrote The Book of the Law. One chapter was written each day, the first being written on April 8, the second on April 9, and the third on April 10. Although there is no official way of celebrating any Thelemic holiday, this particular feast day is usually celebrated by reading the corresponding chapter on each of the three days, usually at noon. June 20/June 21. The Summer solstice in the Northern Hemisphere and the Winter solstice in the Southern Hemisphere. August 12. The Feast of