Sources
The quotes and frequency recommendations in Praxis are drawn from real classical texts and real research. This page lists the primary sources and links to each one.
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Why this page exists
Praxis is built on the idea that small repeated actions matter. The same standard applies to what the app says: every claim should be sourceable, every classical quote correctly attributed, every recommendation traceable to real evidence.
We cite real institutions (FDA, CDC, WHO, NSF, ADA, AAD), real peer-reviewed research, and real classical texts. Where the popular version of a quote turned out to be apocryphal — wrongly attributed to Aristotle, Marcus Aurelius, the Buddha, or Confucius — we replaced it with a sourced alternative. Where an empirical claim couldn’t be verified, we either found a better source or rephrased it more honestly.
If you find an error here, please email praxis.app.support@gmail.com.
Classical sources
Aristotle
The name Praxis and much of the app’s framing comes from Aristotle’s distinction between three modes of activity: theoria (contemplation), poiesis (making for an outcome), and praxis (action whose end is the action itself).
Will Durant (paraphrasing Aristotle)
- “We are what we repeatedly do. Excellence, then, is not an act, but a habit.” — Will Durant, The Story of Philosophy (1926), p. 76. This is Durant’s paraphrase of Aristotle’s concept of hexis (habit / disposition), not Aristotle’s exact words. Read on Internet Archive
Seneca
- “Begin at once to live, and count each separate day as a separate life.” — Seneca, Moral Letters to Lucilius, Letter 101.10. Read on Wikisource
- “It is not that things are difficult that we do not dare; it is because we do not dare that they are difficult.” — Seneca, Letters, Letter 104. Read on Wikisource
- “While we hesitate, life passes.” — Seneca, Letters, Letter 1.2 (“Dum differtur vita transcurrit”). Read on Wikisource
Epictetus
- “First say to yourself what you would be; then do what you have to do.” — Discourses 3.23.1. Read on Internet Classics Archive
- “Make the best use of what is in your power, and take the rest as it happens.” — Discourses 1.1.17 and Enchiridion 1. Read on Internet Classics Archive
- “No man is free who is not master of himself.” — Discourses 4.1.
Marcus Aurelius
Lao Tzu
The Buddha (Pali Canon)
- “What is past is left behind. The future is as yet unreached. Whatever quality is present, see it clearly there.” — Bhaddekaratta Sutta, Majjhima Nikaya 131. Read on Access to Insight
Confucius
- “Learning without thinking is labor lost.” — Analects 2.15.
Research sources for app frequency recommendations
Wellness
- Mindfulness and brain gray matter — Hölzel et al. (2011), “Mindfulness practice leads to increases in regional brain gray matter density,” Psychiatry Research: Neuroimaging, 191(1), 36–43. Read on PubMed Central
- Physical activity and cardiovascular health — World Health Organization, Physical Activity Fact Sheet. The 150 min/week recommendation is verbatim WHO; the ~35% reduction in CVD mortality is from broader meta-analytic evidence cited in WHO’s Physical Activity Guidelines.
- Cold exposure — Søberg et al. (2021), “Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young, healthy, winter-swimming men,” Cell Reports Medicine, 2(10). Read on PubMed
- Bedtime routines — National Sleep Foundation, How to Build a Better Bedtime Routine for Adults.
- Flexibility training — American College of Sports Medicine, Physical Activity Guidelines. ACSM recommends ≥2-3 days per week of stretching, with greater gains attainable from daily practice.
Mental and productivity
- Expressive writing for stress and immunity — Pennebaker (1997), “Writing about emotional experiences as a therapeutic process,” Psychological Science 8(3), 162–166. SAGE abstract
- Reading and longevity — Bavishi, Slade & Levy (2016), “A chapter a day: Association of book reading with longevity,” Social Science & Medicine 164, 44–48. Read on PubMed Central
- Spaced practice — Hermann Ebbinghaus, Über das Gedächtnis (1885) — original spacing-effect research. Full text on Psychology Classics
- Deliberate practice — Ericsson, Krampe & Tesch-Römer (1993), “The Role of Deliberate Practice in the Acquisition of Expert Performance,” Psychological Review 100(3), 363–406. APA PsycNet
- Weekly review for productivity — David Allen, Getting Things Done: The Art of Stress-Free Productivity (2001/2015). Official GTD site
- Planning fallacy — Buehler, Griffin & Ross (1994), “Exploring the ‘planning fallacy’: Why people underestimate their task completion times,” Journal of Personality and Social Psychology 67(3), 366–381. The “Most things take less time than you think” framing in onboarding draws on this and on Kahneman & Tversky’s earlier work on intuitive prediction.
Relationships
- Close relationships and longevity — Harvard Study of Adult Development (1939–present), the longest-running study of adult life. Official site · Robert Waldinger and Marc Schulz, The Good Life (2023).
- Friendship maintenance frequency — Robin Dunbar (Oxford), research on social network layers. The 5-layer “closest friends” tier requires roughly weekly contact. See Dunbar’s Oxford faculty page.
- Couple relationships and rituals of connection — The Gottman Institute. Official site · John Gottman & Nan Silver, The Seven Principles for Making Marriage Work. Gottman’s research recommends daily 20-minute connection rituals and weekly date nights.
Cleaning, health, and household
- Clutter and stress — Saxbe & Repetti (2010), “No Place Like Home: Home Tours Correlate With Daily Patterns of Mood and Cortisol,” Personality and Social Psychology Bulletin 36(1), 71–81. SAGE abstract · Open-access PDF on the UCLA Repetti Lab site · UCLA Center on Everyday Lives of Families (CELF). CELF homepage
- Food safety surface cleaning — FDA Food Code 2022, Chapter 4. Download the full Food Code 2022 PDF (FDA). The 4-hour rule for food-contact surfaces handling Time/Temperature Control for Safety foods is in §4-602.11.
- Household germ contamination — NSF International Household Germ Studies. Germiest items in the home
- Allergens and dust mites — Asthma and Allergy Foundation of America. Dust Mite Allergy — recommends weekly vacuuming with a HEPA filter.
- Mold and respiratory health — Centers for Disease Control. Mold and Your Health
- Cooking fires — National Fire Protection Association. Home Cooking Fires Report — cooking is the leading cause of US home fires (49%), with grease/oil/fat the leading ignition material (45%).
- Laundry hygiene — American Cleaning Institute. Laundry Basics
Personal care
- Flossing and gum health — American Dental Association. Floss page. The ADA recommends daily interdental cleaning. The underlying evidence (per Cochrane systematic reviews) shows a small but statistically significant short-term reduction in gingivitis when flossing is added to brushing.
- Skincare — American Academy of Dermatology. Skin Care Basics
- Dental visits — American Dental Association. Common Questions About Going to the Dentist (MouthHealthy/ADA)
Fasting
- Intermittent fasting and metabolic health — de Cabo & Mattson (2019), “Effects of Intermittent Fasting on Health, Aging, and Disease,” New England Journal of Medicine 381, 2541–2551. PubMed — The review describes the metabolic switching effects of extended fasting windows (the canonical example in the paper is 18:6, but findings generalize to 16-hour daily fasts as well).
- Autophagy and extended fasts — Longo & Mattson (2014), “Fasting: Molecular Mechanisms and Clinical Applications,” Cell Metabolism 19(2), 181–192. Read on PubMed Central
Finance
Stoic concepts in Lumen’s prompt
The on-device AI inside Praxis (Lumen) is built around several Stoic concepts:
- Prosochē (προσοχή — attention, mindfulness) — Epictetus, Discourses throughout.
- Askēsis (ἄσκησις — practice, training) — see Pierre Hadot, Philosophy as a Way of Life (1995) for the canonical modern treatment.
- Dichotomy of control — Epictetus, Enchiridion 1.1.
- Amor fati (love of fate) — Friedrich Nietzsche, Ecce Homo and The Gay Science §276. Amor fati is technically Nietzsche’s concept rather than a classical Stoic one, though it sits in the same family of acceptance-of-reality philosophies. Read Ecce Homo on Project Gutenberg (Ludovici translation)
A note on the apocryphal
A few quotes circulating online with famous names attached turn out to be apocryphal — never said by the person they’re attributed to. Examples we deliberately avoid in Praxis:
- “It does not matter how slowly you go as long as you do not stop” — widely attributed to Confucius but not in the Analects. Origin unknown.
- “Do not dwell in the past…” — attributed to the Buddha but not in the Pali Canon. Replaced in our app with the actual Bhaddekaratta Sutta passage cited above.
- “You have power over your mind, not outside events…” — attributed to Marcus Aurelius but not in the Meditations. A modern paraphrase.
- The “reading 6 minutes reduces stress 68%” statistic was a 2009 marketing-funded press release by Mindlab International, not a peer-reviewed study. Replaced in Praxis with the Bavishi et al. 2016 longevity study on book reading.
If you spot something you believe is misattributed or unsourced, please write to praxis.app.support@gmail.com.
— Matt Peterson