Subtle energy, also known as bioenergy or vital energy, refers to a hypothetical form of energy that is said to be a vital force that differentiates living entities from non-living matter. This concept is often discussed in various forms of alternative medicine, spiritual practices, and certain philosophical traditions. The term "subtle energy" is derived from the Latin word subtilis, meaning "fine" or "delicate." In Hebrew, it can be translated as אנרגיה רכה (energiya raka). In other languages, it may be referred to as energie subtile in French, energía sutil in Spanish, and feine Energie in German. Proponents of subtle energy theories suggest that it flows through and around living beings, influencing their health, emotions, and spiritual well-being. This energy is often associated with concepts such as qi in Traditional Chinese Medicine, prana in Ayurveda, and the life force in various indigenous healing practices. Despite its widespread mention in alternative health circles, subtle energy lacks empirical scientific evidence, and its existence remains a subject of debate and skepticism within the scientific community.