Symbols vs Liminal

Learn logic with Symbols, the app that teaches natural deduction and the rules of inference in an intuitive, accessible way. Our unique Studycards feature visual pictographs and interactive, step-by-step exercises that allow you to grasp each rule easily and quickly. Then, challenge yourself with activities specifically designed to practice those rules, building your skills progressively, and cementing them in your memory with every level completed. Why Symbols? Comprehensive Studycards: Learn essential rules like Modus Ponens, Modus Tollens, Disjunctive Syllogism, and many more through clear explanations and examples. Perfect for students and anyone looking to understand formal logic. Engaging Activities for Skill Mastery: Validity: Sharpen your critical thinking by evaluating pre-solved arguments. This unique activity provides the benefits of repetition without the tedium, helping you apply, recognize, and grow familiar with the rules of inference. Justification: Challenge your understanding with puzzle-like scenarios where you deduce missing argument steps. This deepens your comprehension and refines your application of logical rules within complex arguments. Inference: By this stage, the training wheels are off, and the student has to draw on everything they've learned so far. Their task is to mentally build a valid argument from what’s provided—or to recognize that no valid argument can be formed. What would normally be worked out slowly on paper is now done at the speed of thought. Translation: Translation helps students practice turning statements with indicator words and phrases into logical form. These indicator words, commonly found in logic books and courses, give students a sense of how to translate everyday language into formal logic. Translation breaks this process into levels, allowing students to track their progress and earn new scores as they build proficiency. Download Symbols for free and begin your journey into formal logic. Your free access includes the first level of every activity and the Modus Ponens study card, a must-have for getting started. For more advanced content and features, simply use our in-app purchases to continue building your logic skills. Start your journey of mastering the rules of inference now!

Liminal is a quiet game about thinking. You arrive in the Atrium — a hall of doors. Behind each door is a great mind, reconstructed from their writings to think *with* you: Albert Camus on the café terrace, Nietzsche at altitude, Rumi turning toward the Beloved, Kafka in the unmarked office, the Stoic Marcus Aurelius, and more than a dozen others. Choose a voice, choose how you want to be met — challenged, accompanied, or left mostly to silence — and play. THE GAMES • Words for the Sea — offer a handful of words and receive a short poem in the thinker's voice. • Ask anything — put a real question to a real mind and hear a considered reply. • The Descent — one question, then deeper, and deeper still. • The Dilemma — a classic thought-experiment that branches to a reflection with no clean answer. • The Fork, The Reframe, Agree or Disagree, The Mask, A Minute of Silence — short games that read you back to yourself. ENCOUNTERS — where the voices meet • Two Voices — ask two thinkers one question and watch the second answer the first. • The Symposium — a panel answers, and a neutral narrator names the sharpest disagreement. • Philosophers' Football — draft two sides from the roster and let the eternal match be narrated. • The Oracle, The Gift, The Mirror — smaller rooms for fortune, reflection, and a parting tool to carry. QUIET BY DESIGN No ads. No tracking. No feed. Liminal asks nothing of you but attention. Many games work offline, for free. A NOTE ON THE VOICES The thinkers in Liminal are AI reconstructions written in each mind's spirit — they are not the real people, and nothing they say is professional advice. Liminal is for reflection, not counsel. Live, in-character answers are generated by Anthropic's Claude. The thinkers in Liminal are AI reconstructions — not the real people, and nothing they say is professional advice. Every line is original, written in each voice's spirit — never a verbatim quote from any author. Liminal is for reflection, not counsel. Live, in-character answers are generated by Anthropic's Claude. Sign in with Apple to carry your account and credits across devices. A handful of live answers are free; more are available as a small in-app purchase.